Bildiri Koleksiyonu | Makine Mühendisliği Bölümü / Department of Mechanical Engineering

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  • Öğe
    Assessing dyslexia with machine learning: a pilot study utilizing Google ML Kit
    (IEEE, 2023-12-19) Eroğlu, Günet; Harb, Mhd Raja Abou
    In this study, we explore the application of Google ML Kit, a machine learning development kit, for dyslexia detection in the Turkish language. We collected face-tracking data from two groups: 49 dyslexic children and 22 typically developing children. Using Google ML Kit and other machine learning algorithms based on eye-tracking data, we compared their performance in dyslexia detection. Our findings reveal that Google ML Kit achieved the highest accuracy among the tested methods. This study underscores the potential of machine learning-based dyslexia detection and its practicality in academic and clinical settings.
  • Öğe
    Optimum torque distribution during regenerative braking in a fully electrical vehicle via dynamic programming
    (IEEE, 2023-10-28) Ergün, Ömer; Çaycı, N. Okan; Dinçmen, Erkin; İstif, İlyas
    In electric vehicles, it is important to maximize their regenerative braking performances for obtaining longer driving distances. In this study, for an electric vehicle having motors on the front and rear axles, an optimum torque distribution algorithm based on dynamic programming method is proposed for maximizing the regenerative braking energy. Electric motor limits, efficiency maps, battery model and braking force constraints given in the European regulations are considered in the proposed algorithm. The dynamic programming algorithm code and simulation studies for different braking scenarios are carried out via MATLAB. Simulation studies show that via the proposed torque distribution algorithm, significant improvements in the regenerated braking energy are obtained with respect to the fixed-rate torque distribution algorithm.
  • Öğe
    Design of the near infrared camera DIRAC for East Anatolia Observatory
    (SPIE, 2022) Zhelem, Ross; Content, Robert; Churilov, Vladimir; Kripak, Yevgen; Waller, Lew; Case, Scott; Mali, Slavko; Muller, Rolf; Gonzalez, Mario; Adams, Dave; Binos, Nick; Chin, Timothy; Farrell, Tony; Klauser, Urs; Kondrat, Yuriy; Kunwar, Nirmala; Lawrence, Jon; Lorente, Nuria; Luo, Summer; McDonald, Erica; McGregor, Helen; Nichani, Vijay; Pai, Naveen; Vuong, Minh; Zahoor, Jahanzeb; Zheng, Jessica; Norris, Barnaby; Bryant, Julia; Vaccarella, Annino; Herrald, Nick; Gilbert, James; Yeşilyaprak, Cahit; Güçsav, Bülent; Coker, Deniz; Keskin, Onur; Jolissaint, Laurent
    The 4m DAG telescope is under construction at East Anatolia Observatory in Turkey. DIRAC, the " DAG InfraRed Adaptive optics Camera", is one of the facility instruments. This paper describes the design of the camera to meet the performance specifications. Adaptive and auxiliary optics relay the telescope F/14 input 1:1 into DIRAC. The camera has an all refractive design for the wavelength range 0.9 - 2.4 micron. Lenses reimage the telescope focal plane 33 x 33 as (9 x 9 mm) on a 1k x 1k focal plane array. With magnification of 2x, the plate scale on the detector is 33 mas/pixel. There are 4 standard filters (Y, J, H, K) and 4 narrowband continuum filters. A 12 position filter wheel allows installation of 2 extra customer filters for specific needs; the filter wheel also deploys a pupil viewer lens. Optical tolerancing is carried out to deliver the required image quality at polychromatic Strehl ratio of 90% with focus compensator. This reveals some challenges in the precision assembly of optics for cryogenic environments. We require cells capable of maintaining precision alignment and keeping lenses stress free. The goal is achieved by a combination of flexures with special bonding epoxy matching closely the CTE of the lens cells and crystalline materials. The camera design is very compact with object to image distance <220 mm and lens diameters <25 mm. A standalone cryostat is LN2 cooled for vibration free operation with the bench mounted adaptive optics module (TROIA) and coronagraph (PLACID) at the Nasmyth focus of the DAG telescope.
  • Öğe
    Eastern Anatolia Observatory (DAG): the status in 2022, towards the first light
    (SPIE, 2022) Yeşilyaprak, Cahit; Keskin, Onur; Jolissaint, Laurent
    East Anatolian Observatory's DAG telescope, with its 4m diameter primary mirror and VIS/IR observation capability, Eastern Anatolian Observatory's 4m diameter class DAG telescope, with VIS/IR observation capability, will be located on the Konakll-Karaya summit at an altitude of 3170 m, near the city of Erzurum, Turkey. DAG contains both active optics (aO) and adaptive optics (AO) systems. With the enclosure assembly nearly done, and the dummy mirror integration including the M1 cell integration performed at the end of 2021; DAG telescope's AIV is planned to take place by the end of May/2022 and the Provisional Acceptance by November/2022. DAG is equipped with an in-flange derotator-KORAY (K-mirror Optical RelAY) that will direct the light to the seeing limited Nasmyth platform containing TROIA (TuRkish adaptive Optics system for Infrared Astronomy). The scientific instruments that DAG will receive in 2022, are but not limited to, a stellar coronagraph and a 30"NIR diffraction limited camera. In his paper, a global status update and expected optical performance characteristics will be presented.
  • Öğe
    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.