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Crimea, Ukraine

Terebizh V.Y.,National University of Kyiv | Terebizh V.Y.,Russian Academy of Sciences
Monthly Notices of the Royal Astronomical Society

A compensator (null-corrector) for testing aspheric optical surfaces is proposed, which enables (i) independent verification of optical elements and assembling of the compensator itself, and (ii) ascertaining the compensator position in a control layout for a specified aspheric surface. The compensator consists of three spherical lenses made of the same glass. In this paper, the scope of the compensator expanded to a surface speed ~f/2.3; a conceptual example for a nominal primary of Hubble Space Telescope is given. The autocollimating design allows significant reducing difficulties associated with practical use of lens compensators. © 2014 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society. Source

Kazantseva L.V.,National University of Kyiv | Shatokhina S.V.,Ukrainian Academy of Sciences | Protsyuk Y.I.,State Agency for e Governance of Ukraine | Kovylianska O.E.,State Agency for e Governance of Ukraine | Andruk V.M.,Ukrainian Academy of Sciences
Kinematics and Physics of Celestial Bodies

The catalogue of 59 equatorial coordinates and magnitudes of the Pluto-Charon system for the period 1961–1990 was created based on digitized photographic observations from collections of the Joint Digital Archive of the Ukrainian Virtual Observatory obtained from five telescopes of three Ukrainian observatories. Developed software and scan processing techniques were successfully used. Parametric processing models were analyzed. The mean accuracy for the equatorial coordinates of Tycho-2 reference stars on digitized astronegatives is ±90 mas. The mean error of Tycho-2 BT magnitudes is ±0.32m. Pluto positions were compared with the ephemeris JPL PLU43-DE431. © 2015, Allerton Press, Inc. Source

Bogaienko V.O.,Ukrainian Academy of Sciences | Kudin V.I.,National University of Kyiv | Skopetsky V.V.,Ukrainian Academy of Sciences
Cybernetics and Systems Analysis

Different data types (single-, double-, and extended precision floating point numbers) used in computations substantially affects the following main efficiency estimation criteria: performance, accuracy, and amount of computations. The influence of different variants in the organization of computations on the efficiency of basis-matrix algorithms is studied. The concept of an expert support system is proposed for the organization of computations on linear models to obtain specified parameter values with respect to the accuracy and performance criteria. © 2012 Springer Science+Business Media, Inc. Source

Crawled News Article
Site: http://news.mit.edu/topic/mitmechanical-engineering-rss.xml

MIT’s transfer students form a special and unique community on campus. Each year, MIT Admissions accepts approximately 25 applicants from colleges and universities around the world. The fall 2015 cohort is comprised of 19 talented students from schools such as Bunker Hill Community College, Taras Shevchenko National University of Kyiv, the University of Rochester, Cornell University, and Peking University. In addition to their diverse college backgrounds, transfer students bring a wealth of talents, life experiences, and academic promise. These students have included Math Olympiads participants, first-generation students, a Goldwater Scholar, and a recipient of the Oberndorf Lifeline to Completion Scholarship. One of MIT's star transfer students this year is Jordan Malone, a two-time Olympic medalist in the sport of short track speed skating. Malone had engineering dreams before he had Olympic ones. Even as a 5-year-old avid LEGO builder, he says, he was “sold” on becoming an engineer and would eventually aspire to attend MIT. But with an expiration date on his athletic career, he chose to pursue his Olympic dreams first. “I didn’t want to be a good student and a good athlete, but a great student and a great athlete,” Malone says. He put his education on hold to compete in the Olympics. A native of Denton, Texas, Malone is the only child of a single mom. He is flat-footed and has to contend with asthma, ADHD, and dyslexia. So he’s is not unfamiliar with adversity, rigor, and commitment, all of which he recognizes are part and parcel of an MIT education. “My past entitles me to nothing, but it proves that I'm relentless in the pursuit of a dream,” Malone says. At 30 years old, he has put down his skates and picked up his books in pursuit of a degree in mechanical engineering. But Malone doesn’t consider being admitted to MIT as having reached his goal; graduation is the real finish line. Getting to the finish line poses a slightly different challenge for MIT transfer students than for other undergraduates. Although they participate in freshman orientation and have a home in an academic department, it does take time for them to carve out their place at the Institute. Some have expressed the experience of starting at MIT in this way: “I am not a freshman, yet I don’t really feel like an upperclassman.” But that unique shared identity is one reason transfer students continue to foster a close-knit community — long after they first set foot on campus. To learn more about transferring to MIT, visit the MIT Admissions website.

Il'chenko L.G.,National University of Kyiv | Il'chenko V.V.,National University of Kyiv | Gavrilenko A.V.,Norfolk State University | Gavrilenko V.I.,Norfolk State University
Proceedings of SPIE - The International Society for Optical Engineering

Efficient engineering of metamaterials involves modeling of electric field profiles around these structures. Realistic modeling of the electric field in metamaterials requires accurate knowledge of optical constants of the components for which traditionally the bulk values are taken. Further progress in the developing of metamaterials is characterized by a reduction of the pattern size, dimensions of single layers in multilayered structures etc. It has been understood that optical functions in low-dimensional and nano-sized materials substantially differ from their bulk values increasingly affecting by quantum processes. In this work we develop a complex method for analytical modeling of electric field profiles in metamaterials including quantum processes in nano-sized multi-layered structures. In particular based on first principles density functional theory we obtained simple analytical functions allowing predictions the optical functions variations with the size reduction of single metamaterial components over a wide spectral region. It is shown that optical functions of nano-sized films substantially (by 50 percent and more) differ from those in bulk. The new calculated optical functions of the components are used for electric field profile modeling of nano-sized multilayered structures by nonlocal Green function technique including effects of spatial dispersion. Silicon, silicon dioxide, and water layers are used as an example. The method effectively incorporates real atomic structure reconstruction on surfaces and inner interfaces thus providing with a more realistic picture for modeling. By comparison with experiment it is demonstrated that our method predicts image potential of the nanostructures in better agreement with experiment than if using traditional classic electrodynamics approach neglecting the quantum effects. The results are discussed in comparison with literature. © 2013 SPIE. Source

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