Search

ICGEM is one of the five services coordinated by the International Gravity Field Service (IGFS) of the International Association of Geodesy (IAG)and has been serving to the community for almost two decades.Theservice providesthe scientific community with anarchive of static,temporal, and topographicglobal gravity field models of the Earth in a standardized format withthepossibility to assign DOIs.Furthermore, ICGEMprovidesinteractive calculation and visualisation services of gravity field functionals.Maintenance of such a service and development of new “demand-based” tools are of utmost importance to provide state-of-the-art products. In 2016, the ICGEM portal has been renewed to guarantee a smooth transition to future needs. The last remaining component of the previous ICGEM portal, the G3 Browser, has now been upgraded and integrated into the present ICGEM portal. The G3 Browser aims to compute time series of equivalent water height interactively and gives users the opportunity to compare different gravity model time series as well as impacts of corrections (e.g., GIA, C20) or filters. The G3 Browser is complementary to existing services such as GFZ’s GravIS portal which provides ready-to-use products based on GFZ and COST-G solutions with already applied corrections and filters. On the other hand, the ICGEM G3 Browser includes time series from further processing centres and institutions and different filtering options. This presentation includes the recent progress and how ICGEM and its components contribute to the gravity field related research and educational purposes in universities at graduate and undergraduate level.&nbsp, The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Gravity determination at sea is essential for the definition of physical height systems at sea and adjacent coastal areas. Since 2017, four shipborne gravimetry campaigns were conducted using a Chekan-AM gyro stabilized platform gravimeter containing quartz spring sensors and an iMAR Inertial Measurement Unit serving as strapdown gravimeter. The comparison of both gravimeter types exposed complementary properties of both sensors. With proper maintenance, the gyro stabilized gravimeter shows a very stable linear drift, but its recordings are impaired by steering manoeuvres and harsh sea conditions. In contrast, the strapdown gravimeter recordings are typically reliable during the whole cruise. But with up to 80 hours, the durations of some of the analysed cruises were exceptionally challenging for strapdown measurements. Under these conditions, the accuracy of the strapdown recordings is slightly degraded due to non-linear sensor drift, although the major part of the drift can be eliminated by thermal calibration or stabilisation. Under smooth sea conditions at the Baltic Sea with cruise durations of less than 35 hours, a precision of 0.4 to 0.5 mGal was obtained for both individual gravimeter results. A combination of both gravimeter types using complementary high- and low-pass filtering provided drift reduction and the possibility of gravity determination during the entire cruise. In the latest campaign, two strapdown gravimeters were installed in addition to the gyro stabilized platform gravimeter allowing for a detailed comparison of the drift behaviour of all three gravimeters., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

The almost 20-year-old ICGEM is one of the five services coordinated by the International Gravity Field Service (IGFS) of the International Association of Geodesy (IAG). Hosted by the GFZ Potsdam, it provides the scientific community with a comprehensive archive of static, temporal, and topographic global gravity field models (GGMs) of the Earth. Furthermore, ICGEM offers an interactive calculation and visualization service of gravity field functionals and tutorials on the theory. The current service cannot address the advancements in the field of gravity modelling and the wide range of applications of such models and their deliverables in Earth sciences. There is an immediate need to expand, modernise, and upgrade the existing database, research data and metadata included in all facets of the service. In this presentation, we will introduce an upcoming project that will improve, actualize and expand ICGEM with providing additional data and a sustainable infrastructure that follows the FAIR Principles (Findable, Accessible, Interoperable and Reusable). New gravity field related data of transdisciplinary importance (e.g., altimetry grids, DEMs) as well as new calculated gravity field functionals (e.g., isostatic gravity anomalies) and readily computed gravity functional grids will be added. The evaluation tools will be improved and data and metadata standards will be established. The new portal will be interlinked to other national and international research data initiatives (e.g., GGOS, NFDI4Earth). Finally, an improved public outreach strategy shall be developed. The realization of this project shall be done in close contact and communication with the international Earth Gravity Field community., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)

Data publications with digital object identifiers (DOI) are best practice for FAIR sharing data. Originally developed with the purpose of providing permanent access to (static) datasets described in scholarly literature, DOI today are more and more assigned to dynamic data. These DOIs are providing a citable and traceable reference of various types of sources (data, software, samples, equipment) and means of rewarding the originators and institutions. As a result of international groups, like the Coalition on Publishing Data in the Earth, Space and Environmental Sciences (COPDESS) and the Enabling FAIR Data project, data with assigned DOIs are fully citable in scholarly literature and many journals require the data underlying a publication to be available – even before accepting an article. Initial metrics for data citation allows data providers to demonstrate the value of the data collected by institutes and individual scientists.This is especially relevant for the geodesy, because, geodesy researchers are often much more involved in operational aspects and data provision than researchers in other fields might be. Therefore, compared to other scientific disciplines, geodesy researchers appear to be producing less “countable scientific” output. Consequently, geodesy data and equipment require a structured and well-documented mechanism which will enable citability, scientific recognition and reward that can be provided by assigning DOI to data and data products.To address these challenges and to identify opportunities for improved coordination and advocacy within the geodetic community, the International Association of Geodesy’s (IAG) Global Geodetic Observing System (GGOS) has established a Working Group on “Digital Object Identifiers (DOIs) for Geodetic Data Sets” in 2019. This Working Group is designated to establish best practices and advocate for the consistent implementation of DOIs across all IAG Services and in the greater geodetic community.The main objectives and activities of this working group are:(1) to identify what the community needs from consistent usage of DOIs for data in terms of being able to discover data, permanently cite data, and acknowledge the data providers (2) to develop recommendations for DOI minting strategies for different geodetic data types and granularity across IAG Services (static, dynamic, observational data, data products, combination products, networks) (3) to develop recommendations for a consistent method for data citation across all IAG Services, to support data providers, and to provide quantitative support detailing the use of geodetic datasets and other resources. (4) to develop recommendations for connecting metadata standards for data discovery (e.g. DataCite, ISO19115) with community metadata standards (GeodesyML, Station Logs) This presentation will provide an update on recent topics and first recommendations from the GGOS DOI Working Group.

The global gravitational potential generated by the attraction of the Earth’s topographic masses has been computed in spectral domain. The mass-source information is provided by the 1 arcmin resolution Earth2014 relief model and four averaged density values for rock, ocean, lake, and ice areas. The topography and bathymetry are split into confocal ellipsoidal shells of a defined thickness. Based on the provided mass-source information, the gravitational potential is expanded for each shell and then summed up to represent the complete gravitational potential of the topography (and bathymetry). In this contribution, we present the impact of different shell thicknesses to the model accuracy and computation time. Moreover, we expanded our topographic gravity field model up to spherical harmonic degree and order 5,494. Such short scale mass information represented by the topography can be used to complement high-resolution combined static gravity field models for the very high-frequency components of the gravity field. As an example, we enhanced (augmented) EIGEN-6C4 model with the high frequency components retrieved from the topographic model. The deflections of vertical values computed from the augmented model are compared w.r.t. ground truth observations in Germany, Southern Colorado and Iowa (USA) which suggest as expected a considerable improvement over rugged mountainous regions and comparable residuals in areas of moderate topography.

In this study, Al matrix composites consisting of different amounts of Zn, Cu, and Mg were produced using the powder metallurgy technique. In the alloying, powders were ball milled for 120 min via mechanical alloying. After alloying process, the powders were pressed at 800 MPa at room temperature. Sintering (2 h at 600 degrees C in argon atmosphere), solution treatment (2 h at 480 degrees C), and aging processes (3, 6, 9, and 12 h, respectively, at 120 degrees C) were applied to the samples. The hardness and tribo-metallurgy properties of the products were investigated. After sintering, the hardness values of the three alloys were close to each other; however, the solution treatment after sintering caused the hardness values to increase significantly. It was determined that the Al-2Zn-5Cu-4Mg alloy had the highest hardness increase with the 6-h aging heat treatment. The wear resistance of the materials in all the compositions had increased. The highest wear resistance and lowest friction coefficient were obtained for the Al-2Zn-5Cu-4Mg alloy with the 6-h aging heat treatment. C1 [Kaplan, Yavuz] Pamukkale Univ, Fac Technol, Dept Mech & Mfg Engn, Denizli, Turkey. [Aksoz, Sinan] Pamukkale Univ, Fac Technol, Dept Met & Mat Engn, Denizli, Turkey. [Ada, Hakan] Kastamonu Univ, Dept Mech Engn, Fac Engn & Architecture, Kastamonu, Turkey. [Ince, Emre; Ozsoy, Serkan] Kastamonu Univ, Inst Sci & Technol, Kastamonu, Turkey.

FAMOS (Finalizing Surveys for the Baltic Motorways of the Sea) is a recently run project which was supported by EU to improve the safety of ship navigation on the Baltic Sea. One task of FAMOS was to work on a common height reference for the Baltic Sea, the Baltic Sea Chart Datum 2000 (BSCD2000), which will be based on a new gravimetric geoid for this sea. The German institutions German Research Centre for Geosciences (GFZ), Federal Agency for Cartography and Geodesy (BKG), Federal Maritime and Hydrographic Agency (BSH) and Technical University of Darmstadt performed several marine gravimetry surveys to contribute to this project. The primary measurement equipment was GFZ’s Chekan-AM gravimeter. On two of these campaigns an iMAR strapdown inertial measurement unit (IMU) was used together with the Chekan. The data records from both instruments are of very good consistency. Since the FAMOS project ended ahead of the planned schedule already in 2019, finalization of the new chart Datum is now coordinated by the Chart Datum Working Group within the Baltic Sea Hydrographic Commission. It is planned to implement the new BSCD2000 by 2023.

Within the European Union FAMOS project, GFZ performed two gravimetry campaigns on commercial ferries in the Baltic Sea in 2017 and 2018. The nature of such “non-dedicated” campaigns is different from “dedicated” campaigns which are performed on research vessels with tracks planned according to gravity measurement needs. The non-dedicated campaigns use non-survey vessels (e.g. ferries) or survey vessels running for other purposes (e.g. hydrographic measurements). Measurements conducted on such conditions may require additional corrections besides the typical marine gravimetry corrections. We investigated two additional corrections, namely the vertical accelerations due to the motion of the ferry in the vertical direction and the dynamical effect due to the cross-coupling between horizontal and vertical acceleration components. To assess the usefulness of non-dedicated campaigns, we analysed gravity measurements collected on two commercial ferries and demonstrated that the standard processing without the above mentioned two corrections, as used in dedicated campaigns, already delivers good quality end products that fulfil the requirements of a typical marine gravimetry survey with an uncertainty of about 1 mGal for a much lower cost. Therefore, the data published in this contribution is a product of the same algorithm we use for dedicated campaign measurements. Based on our findings, we suggest that gravimetry campaigns on commercial ferries can be used to complement dedicated marine gravimetry campaigns and contribute to geodetic purposes.

Natural language processing which is an engineering field which is concerned with the design and implementation of computer systems whose main function is to analyze, understand, interpret and produce a natural language. Literature review was conducted using Turkish natural language studies documentation method. Documentation on the current method of examination to be reliable scientific research and thesis studies on natural language processing in Turkey were examined by scanning pages of the thesis of Higher Education. Evaluated in terms of the subjects of the study samples obtained as a result of the literature review Morphological analysis studies, syntactic analysis studies, semantic analysis studies and problem analysis criteria were determined and presented. Yilmaz Ince, E "Turkish Natural Language Processing Studies" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-1 , December 2019, URL: https://www.ijtsrd.com/papers/ijtsrd29831.pdf

In this research, it is aimed to determine the success level of the students according to the answers given in the previous exams with TOPSIS method, to send the question to the related student by the authorized teacher according to the determined success level, to analyze the students periodical weekly monthly yearly performance with graphical data and to create a data bank and to determine the overall performance of the student. Developmental research technique was used, which is one of the design based research method derivatives including the design of educational tools. This study consists of question suggestion and question selection tool components. Adaptive question suggestion system perform generation, storage, classification, disclosure and publication of the content. The software has been successfully tested by 350 students and teachers by using 1000 questions prepared by the educator about the courses and subjects previously defined. As a result, it is seen that students check all the questions related to courses and subjects in the application database and submit the most appropriate question to the requestor in response to the question requests. Also it is observed that the TOPSIS algorithm quickly determined the desired number of questions from the question bank formed by the authorized teacher in accordance with the required criteria, and the process of creating a trial or subject test was performed successfully. ‡akir, A. | Yilmaz Ince, E. | Babanyyazova, Y. "Adaptive Question Recommendation System Based on Student Achievement" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-4 | Issue-1 , December 2019, URL: https://www.ijtsrd.com/papers/ijtsrd29789.pdf

OBJECTIVE This study aimed to define the status of juvenile myelomonocytic leukemia (JMML) patients in Turkey in terms of time of diagnosis, clinical characteristics, mutational studies, clinical course, and treatment strategies. MATERIALS AND METHODS Data including clinical and laboratory characteristics and treatment strategies of JMML patients were collected retrospectively from pediatric hematology-oncology centers in Turkey. RESULTS Sixty-five children with JMML diagnosed between 2002 and 2016 in 18 institutions throughout Turkey were enrolled in the study. The median age at diagnosis was 17 months (min-max: 2-117 months). Splenomegaly was present in 92% of patients at the time of diagnosis. The median white blood cell, monocyte, and platelet counts were 32.9x109/L, 5.4x109/L, and 58.3x109/L, respectively. Monosomy 7 was present in 18% of patients. JMML mutational analysis was performed in 32 of 65 patients (49%) and PTPN11 was the most common mutation. Hematopoietic stem cell transplantation (HSCT) could only be performed in 28 patients (44%), the majority being after the year 2012. The most frequent reason for not performing HSCT was the inability to find a suitable donor. The median time from diagnosis to HSCT was 9 months (min-max: 2-63 months). The 5-year cumulative survival rate was 33% and median estimated survival time was 30±17.4 months (95% CI: 0-64.1) for all patients. Survival time was significantly better in the HSCT group (log-rank p=0.019). Older age at diagnosis (>2 years), platelet count of less than 40x109/L, and PTPN11 mutation were the factors significantly associated with shorter survival time. CONCLUSION Although there has recently been improvement in terms of definitive diagnosis and HSCT in JMML patients, the overall results are not satisfactory and it is necessary to put more effort into this issue in Turkey.

Öz bulunamadı.