Arama Sonuçları

Listeleniyor 1 - 10 / 10
  • Yayın
    Integrated opto-dynamic modeling of the 4-m DAG telescope image quality performance
    (SPIE-Int Soc Optical Engineering, 2016) Zago, Lorenzo; Guex, Benjamin; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Keskin, Onur
    The Turkish DAG 4-m telescope is currently through the final design stage. It is to be located on a 3170 m mountain top in Eastern Anatolia. The telescope will be a state-of-The art device, alt-Az mount with active primary and adjustable secondary and tertiary mirrors. Its optics design is specially aimed at being compatible with advance adaptive optics instrumentation. The ultimate performance of such a telescope results of multiple concurrent effects from many different components and active functions of the complex system. The paper presents a comprehensive integrated (end-To-end) model of the telescope, comprising in one computational sequence all structural, electrodynamics and oactive optics performance that produce the image quality at the focal plane. The model is entirely programmed in Matlab/Simulink and comprises a finite element model of structure and mirrors, dynamics modal reduction, deformation analyses of structural and optical elements, active optics feedback control in the Zernike modal space.
  • Yayın
    ICamp - The educational web for higher education
    (Springer Verlag, 2006) Kieslinger, Barbara; Wild, Fridolin; Arsun, Onur İhsan
    iCamp is an EC-funded research project in the area of Technology Enhanced Learning (TEL) that aims to support collaboration and social networking across systems, countries and disciplines in higher education. The concept of an iCamp Space will build on existing interfaces and integrate shared community features. Interoperability amongst different open source learning systems and tools is the key to successful sustainability of iCamp. The content for this collaboration within social communities is provided via distributed networked repositories including, for example, content brokerage platforms, online libraries, and learning object databases. The innovative pedagogical model of iCamp is based on social constructivist learning theories. iCamp creates an environment for a new way of social networking in higher education that puts more emphasis on self-organised, self-directed learning, social networking and cross-cultural collaboration.
  • Yayın
    Strategic alignment and project management offices: case studies from successful implementations in Turkey
    (IEEE, 2013-03-18) Karayaz, Gamze; Güngör, Özge
    Due to an increased need for learning modern project management methodologies, companies have been forced to improve their knowledge of Project Management Offices (PMO). Global business environment resulted with increased importance of project management methodologies, aligned with competitive strategies. Today, many organizations have recognized the importance of implementing PMO's for effective project control and better stakeholder (executives) support for projects. PMOs also undertake strategic roles such as incorporating higher management support to achieve strategic goals, integrating business strategies into project management efforts, and prioritization of projects. This paper examines PMOs in the process of strategic alignment. Moreover, the contribution of PMOs to achieve strategic goals is explored. Our initial findings are promising represented in a framework, and demonstrated by a case study application review using IT and telecommunication companies selected from Turkey. The research offers future directions and implications of a well-established successful PMO system.
  • Yayın
    DAG 4m telescope: assembly, integration and testing
    (SPIE-Int Soc Optical Engineering, 2018-07-06) Pirnay, Olivier; Lousberg, Grégory P.; Gabriel, Eric; Marchiori, Gianpietro; Busatta, Andrea; Yeşilyaprak, Cahit; Keskin, Onur
    AMOS with EIE as a main subcontractor, was awarded a contract in November 2014 for the design, manufacturing and installation of a 4m-class telescope for the Turkish Eastern Anatolia Observatory (DAG) situated at 3170 m above the sea level in Palandöken mountains. The telescope is based on a Ritchey-Chretien configuration with two folded Nasmyth focal planes and a focal length of 56m. Diffraction-limited performances will be reached thanks to the combination of the active optics system and the adaptive optics system that will be implemented on one of the Nasmyth ports. The active optics system aims at controlling the shape of the primary mirror by means of 66 axial force actuators and positioning actively the secondary and tertiary mirrors by means of hexapods. More than 30 years of experience in testing instruments and telescopes, including optical testing, alignment, metrology, mechanical static and dynamic measurements, system identification, etc. allow to implement an adequate verification strategy combining component level verifications with factory and site test in the most efficient and reliable manner. As a main contractor, AMOS is in charge of the overall project management, the system engineering, the optical design and the active optics development. As a main sub-contractor and partner of AMOS, EIE is in charge of the development of the mount. The factory test therefore takes place in EIE premises. In this paper is shortly presented the overall design of the telescope with a review of the specification, the optical design and a description of the major sub-systems, including the optics. The assembly, integration et test plan is outlined. The assembly sequence and the tests of the active optics and the mount are discussed. Finally, the site integration and tests are explained. The process to assess the image quality of the telescope and the verification instrument developed for this purpose by AMOS are presented.
  • Yayın
    Observatory building design: A case study of DAG with infrastructure and facilities
    (SPIE, 2016-08-19) Şahmalı, Ali Erkan; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Keskin, Onur
    Eastern Anatolian Observatory (DAG), will be built in one of the well-known mountain ridges of Erzurum, Turkey, at latitude of 39°46'50, longitude of 41°13'35 and an altitude of 3.151 meters. As well as erecting the largest telescope of Turkey, the DAG project aims to establish an observatory complex both small in size and functional enough to give service to all astronomy community. In this paper, the challenge is explained in details: geological and geographical limitations, environmental and meteorological constraints, engineering and structural considerations, energy efficiency and sustainability.
  • Yayın
    DAG 4m telescope: optics completion, on-site integration and test
    (SPIE, 2022) Pirnay, Olivier; Albart, Pierre; Bastin, Christian; De Ville, Jonathan; Gabriel, Eric; Leseur, Thibault; Lousberg, Grégory P.; Méant, Laurence; Orban, Sabrina; Tortolani, Jean-Marc; Amalfi, Manfredi; Marchiori, Gianpietro; Rampini, Francesco; Busatta, Andrea; Yeşilyaprak, Cahit; Keskin, Onur
    AMOS with EIE as main subcontractor has recently completed the erection of the 4 m telescope located at the Turkish Eastern Anatolia Observatory (DAG) set up by the Ataturk University Astrophysics Research and Application Centre (ATASAM) of Erzurum. The telescope design is based on a Ritchey-Chrétien configuration with two folded Nasmyth focal planes and a focal length of 56m. The optical train is composed of three mirrors: the primary mirror (M1) with an optical aperture of 4m, a convex secondary mirror (M2), and a large flat folding mirror (M3). Diffraction-limited performances in optical and near infrared spectral bands will be achieved thanks to the combination of active and adaptive optics systems. The active optics system is controlling the shape of the primary mirror by means of 66 axial force actuators and position actively the secondary and tertiary mirrors by means of hexapods. The adaptive optics system will be implemented at one of the two Nasmyth ports. As main contractor, AMOS is in charge of the overall project management, the system engineering, the optical design and the active optics development. As main sub-contractor and partner of AMOS, EIE is in charge of the development of the mount. Following the factory acceptance in Europe, the telescope was dismounted and delivered in early 2021. The activities onsite were carried out according to the assembly, integration and verification plan (AIV plan). In the meantime, the fabrication of the 4 m primary mirror was completed, and the full set of mirrors was forwarded on-site before the end of the year 2021. In this paper is presented a brief description of the design and performances of the telescope followed by the project progress status at the time the optics are being integrated in the telescope for the first time. This includes the review of the mirrors as-built quality and the excepted performances of the telescope mount after alignment and tuning. The path forward final acceptance is explained with the presentation of the optical alignment method and the test carried-out on-sky.
  • Yayın
    Coordination in building an observatory: A case study of Eastern Anatolian Observatory (DAG)
    (SPIE-Int Soc Optical Engineering, 2018) Şahmalı, Ali Erkan; Yeşilyaprak, Cahit; Keskin, Onur
    Eastern Anatolian Observatory (DAG) is designed to build on one of the summits of Palandoken Mountains in Erzurum, Turkey, at an altitude of 3,151 meters. The building is under construction since 2015 and expected to be completed in 2020. The building is designed as an integrated building, having operational departments, services, mechanical and electrical infrastructure for observations as well as cleaning and coating units, adjacent to the main observatory building. As one might expect this integration creates serious coordination problems between architect, engineers, telescope, enclosure, and cleaning & coating unit manufacturers. The construction progress of the investment is almost 20%. There are quite an amount of "lessons learned" in this period, and need to be developed by the parties, for their existing and future works. The building has so many challenges such as geological and geographical limitations, environmental and meteorological constraints, engineering and structural considerations, energy efficiency and sustainability, materials used and their performances at these limitations.
  • Yayın
    Project management of DAG: Eastern Anatolia Observatory
    (SPIE, 2016) Keskin, Onur; Yeşilyaprak, Cahit; Yerli, Sinan Kaan; Zago, Lorenzo; Güver, Tolga; Aliş, Sinan
    The four meter DAG (Eastern Anatolia Observatory in Turkish) telescope is not only the largest telescope in Turkey but also the most promising telescope in the northern hemisphere with a large potential to offer scientific observations with its cutting edge technology. DAG is designed to be an AO telescope which will allow both infrared and visible observations with its two Nasmyth platforms dedicated to next generation focal plane instruments. In this paper, status updates from DAG telescope will be presented in terms of; (i) in house optical design of DAG, (ii) tender process of telescope, (iii) tender process of enclosure, and (iv) tender process of the observatory building. Also status updates from the focal plane instruments project and possible collaboration activities will be presented.
  • Yayın
    Team composition and team performance: Achieving better results in an international higher education environment
    (Editura Niculescu, 2013-10-31) Scarlat, Cezar; Falcıoğlu, Pınar
    In line with former experiments, this stud), covers a period of four years (2008-2012) while teaching Project Management courses to international students at Mikkeli University of Applied Sciences, Finland - aiming to explore the possibility to apply the Belbin's theory on building successful small project teams in a multicultural higher education environment - in order to achieve better results - in terms of both satisfaction and performance. Besides exploring this possibility, the study has as objectives: (i) to assess the students' performance while working in teams; (ii) to assess the students' satisfaction of working in teams built according to different criteria; (iii) to check if there is any relationship between team members' performance and the way team is built. The influence of the cultural background was behind the scope of this work. The results are positive: the theory is applicable in the above conditions,. students' satisfaction depends on the way the team is built; building the teams according to the theory of team members' roles leads to better performance. The results of the study are important jar academic researchers as well as practitioners - higher education professors and decision makers, aiming at improving the quality of the higher education processes.
  • Yayın
    Project management and status update for DAG (Eastern Anatolia Observatory) the 4 meter VIS/IR optical telescope
    (SPIE-Int Soc Optical Engineering, 2018) Keskin, Onur; Yeşilyaprak, Cahit; Jolissaint, Laurent
    The new 4 m Turkish telescope, DAG (East Anatolian Observatory, Fig. 2), will be located on the summit of the mountain Konakli-Karakaya, at an altitude of 3170 m, near the city of Erzurum, Turkey. First light is expected for August 2020. The telescope is a multi-purpose instrument, and will run observations both in the visible (VIS) and near infrared (NIR) domains, in seeing limited (SL) and adaptive optics (AO) correction mode. In his paper, status updates from DAG telescope will be presented in terms of; (i) DAG telescope optics, (ii) Nasmyth focal planes and platforms, (iii) current progress of the telescope, (iii) current progress of enclosure, (iv) current progress of the observatory building, (v) current process of the astronomical instruments & tendering phase, and (Vi) status of the Optomechatronics Research Laboratory - OPAL.