An old boys magazine called The Hawk is published aperiodically. the most recent issue was No. 9, published in October 2005. The magazine includes, among other things, news of current University teams and results, obituaries of notable members, and Club notices.
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Taylor and Socolar remark that the 3D monotile aperiodically tiles three-dimensional space. However the tile does allow tilings with a period, shifting one (non-periodic) two dimensional layer to the next, and so the tile is only "weakly aperiodic". Physical copies of the three-dimensional tile could not be fitted together without allowing reflections, which would require access to four-dimensional space.
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The rhombille tiling is the dual of the trihexagonal tiling. It is one of many different ways of tiling the plane by congruent rhombi. Others include a diagonally flattened variation of the square tiling (with translational symmetry on all four sides of the rhombi), the tiling used by the Miura-ori folding pattern (alternating between translational and reflectional symmetry), and the Penrose tiling which uses two kinds of rhombi with 36° and 72° acute angles aperiodically. When more than one type of rhombus is allowed, additional tilings are possible, including some that are topologically equivalent to the rhombille tiling but with lower symmetry.
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Combining Berger's undecidability result with Wang's observation shows that there must exist a finite set of Wang tiles that tiles the plane, but only aperiodically. This is similar to a Penrose tiling, or the arrangement of atoms in a quasicrystal. Although Berger's original set contained 20,426 tiles, he conjectured that smaller sets would work, including subsets of his set, and in his unpublished Ph.D. thesis, he reduced the number of tiles to 104. In later years, increasingly smaller sets were found... (Showed an aperiodic set of 13 tiles with 5 colors)... (Showed an aperiodic set of 11 tiles with 4 colors)} For example, a set of 13 aperiodic tiles was published by Karel Culik II in 1996.
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Colm Mulcahy (born September 1958) is an Irish mathematician, academic, columnist, book author, public outreach speaker, and amateur magician, long on the faculty of Spelman College. In addition to algebra, number theory, and geometry, his interests include mathemagical card magic and the culture of mathematics–particularly the contributions of Irish mathematicians and also the works of iconic mathematics writer Martin Gardner. He has blogged for the Mathematical Association of America, The Huffington Post, Scientific American, and (aperiodically) for The Aperiodical;The Aperiodical his puzzles have been featured in The New York Times.Celebrations of Mind Honor Math’s Best Friend, Martin Gardner by Colm Mulcahy, Scientific American, 29 October 201311 Stories By Colm Mulcahy In Scientific American Mulcahy serves on the Advisory Council of the Museum of Mathematics in New York City.
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The different components within the category of VEPs were first described by Spehlmann in 1965 who compared human ERPs when viewing patterned and diffuse stimuli that were quickly flashed on the screen while a person was viewing the general area where the flash was to appear. However, it was not until Jeffreys and Axford (1972) that the earliest individual components of those VEPs were delineated, including the C1 component. Jeffreys and Axford had human participants view stimulus patterns of squares for a very short time (25ms), aperiodically, in different parts of the participant's visual fields while being recorded using electrodes placed towards the back of the head. Specifically, they recorded from three electrode sites placed on the longitudinal midline of the head: one 3 cm anterior to the inion (the bony projection at the posteroinferior part of the skull), and two 3 cm to either side of the midline. After averaging between like trials (trials where the stimuli were presented in the same part of the visual field) and looking at the ERPs, Jeffreys and Axford postulated that there are two distinct components in the first 150 milliseconds, the C1 and the C2.
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