Academic literature on the topic 'Regular projections'

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Journal articles on the topic "Regular projections"

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Takimura, Yusuke. "Regular projections of the knot 62." Journal of Knot Theory and Its Ramifications 27, no. 14 (December 2018): 1850081. http://dx.doi.org/10.1142/s0218216518500815.

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A knot [Formula: see text] is a minor of a knot [Formula: see text] if any regular projection of [Formula: see text] is also a regular projection of [Formula: see text]. This defines a pre-ordering on the set of all knots. For each knot of five or less crossings, the set of all regular projections of it is determined by Taniyama [A partial order of knots, Tokyo J. Math. 12(1) (1989) 205–229]. Thus, the pre-ordering is determined up to five crossing knots. In this paper, we determine the set of all regular projections of the knot [Formula: see text].
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Wang, Xingchang, Tao Yu, Kwokwai Chung, Krzysztof Gdawiec, and Peichang Ouyang. "Stereographic Visualization of 5-Dimensional Regular Polytopes." Symmetry 11, no. 3 (March 18, 2019): 391. http://dx.doi.org/10.3390/sym11030391.

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Regular polytopes (RPs) are an extension of 2D (two-dimensional) regular polygons and 3D regular polyhedra in n-dimensional ( n ≥ 4 ) space. The high abstraction and perfect symmetry are their most prominent features. The traditional projections only show vertex and edge information. Although such projections can preserve the highest degree of symmetry of the RPs, they can not transmit their metric or topological information. Based on the generalized stereographic projection, this paper establishes visualization methods for 5D RPs, which can preserve symmetries and convey general metric and topological data. It is a general strategy that can be extended to visualize n-dimensional RPs ( n > 5 ).
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Chalmers, Bruce L., and Boris Shekhtman. "Minimal projections and absolute projection constants for regular polyhedral spaces." Proceedings of the American Mathematical Society 95, no. 3 (March 1, 1985): 449. http://dx.doi.org/10.1090/s0002-9939-1985-0806085-4.

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Hept, Kerstin, and Thorsten Theobald. "Tropical bases by regular projections." Proceedings of the American Mathematical Society 137, no. 07 (February 18, 2009): 2233–41. http://dx.doi.org/10.1090/s0002-9939-09-09843-8.

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Affentranger, Fernando, and Rolf Schneider. "Random projections of regular simplices." Discrete & Computational Geometry 7, no. 3 (March 1992): 219–26. http://dx.doi.org/10.1007/bf02187839.

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B�r�czky, Jr., K., and M. Henk. "Random projections of regular polytopes." Archiv der Mathematik 73, no. 6 (December 1, 1999): 465–73. http://dx.doi.org/10.1007/s000130050424.

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TANIYAMA, KOUKI, and CHIZU YOSHIOKA. "REGULAR PROJECTIONS OF KNOTTED HANDCUFF GRAPHS." Journal of Knot Theory and Its Ramifications 07, no. 04 (June 1998): 509–17. http://dx.doi.org/10.1142/s0218216598000279.

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We construct an infinite set of knotted handcuff graphs such that the set of the regular projections of the handcuff graphs in the set equals the set of the regular projections of all knotted handcuff graphs. We also show that no finite set of knotted handcuff graphs have this property.
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Filliman, P. "The largest projections of regular polytopes." Israel Journal of Mathematics 64, no. 2 (June 1988): 207–28. http://dx.doi.org/10.1007/bf02787224.

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Hofmeister, M. "Enumeration of Concrete Regular Covering Projections." SIAM Journal on Discrete Mathematics 8, no. 1 (February 1995): 51–61. http://dx.doi.org/10.1137/s0895480193248186.

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Pędzich, Paweł. "Image of the World on polyhedral maps and globes." Polish Cartographical Review 48, no. 4 (December 1, 2016): 197–210. http://dx.doi.org/10.1515/pcr-2016-0014.

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Abstract Application of polyhedrons as image surface in cartographic projections has a tradition of more than 200 years. The first maps relying on polyhedrons appeared in the 19th century. One of the first maps which based on an original polyhedral projection using a regular octahedron was constructed by the Californian architect Bernard Cahill in 1909. Other well known polyhedral projections and maps included Buckminster Fuller’s projection and map into icosahedron from 1954 and S. Waterman’s projection into truncated octahedron from 1996, which resulted in the “butterfly” map. Polyhedrons as image surface have the advantage of allowing a continuous image of continents of the Earth with low projection distortion. Such maps can be used for many purposes, such as presentation of tectonic plates or geographic discoveries. The article presents most well known polyhedral maps, describes cartographic projections applied in their preparation, as well as contemporary examples of polyhedral maps. The method of preparation of a polyhedral map and a virtual polyhedral globe is also presented.
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Dissertations / Theses on the topic "Regular projections"

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Bani-Hashemian, Mohammad Hossein. "Projections of Immersed Surfaces and Regular Homotopy." Thesis, Uppsala University, Department of Mathematics, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-110697.

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This thesis is based on U. Pinkall’s study of the classification of immersions of compact surfaces into R3 up to regular homotopy. The main idea of the classification is to associate to any immersion f a quadratic form qf on the first homology group of the underlying surface Σ with Z2 coefficients, whose associated bilinear form is the nondegenerate intersection form in H1(Σ,Z2), having the property that it depends only on the regular homotopy class of f. In the case of orientable surfaces qf turns out to be a Z2-quadratic form. In this thesis we construct the Z2-quadratic form using the notion of Spin - structure, and via D. Johnson’s correspondence between Spin - structures on a surface and Z2-quadratic forms on the first homology group of the surface. Then by studying the relation between surface immersions into 3-space and their projections to a 2-plane, we give a formula for computing the value of the quadratic form on any homology class c ∈ H1(Σ,Z2), which we will use to construct an example of two nonregularly homotopic immersions of the 2 - dimensional torus T2 into R3 with identical plane projections.

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Oudrane, M'hammed. "Projections régulières, structure de Lipschitz des ensembles définissables et faisceaux de Sobolev." Electronic Thesis or Diss., Université Côte d'Azur, 2023. http://www.theses.fr/2023COAZ4034.

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Dans cette thèse, nous abordons des questions autour de la structure métrique des ensembles définissables dans les structures o-minimales.Dans la première partie, nous étudions les projections régulières au sens de Mostowski, nous prouvons que ces projections n'existent que pour les structures polynomialement bornées, nous utilisons les projections régulières pour refaire la preuve de Parusinski de l'existence des recouvrements réguliers. Dans la deuxième partie de cette thèse, nous étudions les faisceaux de Sobolev (au sens de Lebeau). Pour les fonctions de Sobolev de régularité entière positive, nous construisons ces faisceaux sur le site définissable d'une surface en nous basant sur des observations de base des domaines définissables dans le plan
In this thesis we address questions around the metric structure of definable sets in o-minimal structures. In the first part we study regular projections in the sense of Mostowski, we prove that these projections exists only for polynomially bounded structures, we use regular projections to re perform Parusinski's proof of the existence of regular covers. In the second part of this thesis, we study Sobolev sheaves (in the sense of Lebeau). For Sobolev functions of positive integer regularity, we construct these sheaves on the definable site of a surface based on basic observations of definable domains in the plane
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Salas, Videla David. "Détermination sous-différentielle, propriété Radon-Nikodym de faces, et structure différentielle des ensembles prox-réguliers." Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT299/document.

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Ce travail est divisé en deux parties: Dans la première partie, on présente un résultat d'intégration dans les espaces localement convexes valable pour une longe classe des fonctions non-convexes. Cela nous permet de récupérer l'enveloppe convexe fermée d'une fonction à partir du sous-différentiel convexe de cette fonction. Motivé par ce résultat, on introduit la classe des espaces ``Subdifferential Dense Primal Determined'' (SDPD). Ces espaces jouissent des conditions nécessaires permettant d'appliquer le résultat ci-dessus. On donne aussi une interprétation géométrique de ces espaces, appelée la Propriété Radon-Nikod'ym de Faces (FRNP). Dans la seconde partie, on étudie dans le contexte d'espaces d'Hilbert, la relation entre la lissité de la frontière d'un ensemble prox-régulier et la lissité de sa projection métrique. On montre que si un corps fermé possède une frontière $mathcal{C}^{p+1}$-lisse (avec $pgeq 1$), alors sa projection métrique est de classe $mathcal{C}^p$ dans le tube ouvert associé à sa fonction de prox-régularité. On établit également une version locale du même résultat reliant la lissité de la frontière autour d'un point à la prox-régularité en ce point. On étudie par ailleurs le cas où l'ensemble est lui-même une $mathcal{C}^{p+1}$-sous-variété. Finalement, on donne des réciproques de ces résultats
This work is divided in two parts: In the first part, we present an integration result in locally convex spaces for a large class of nonconvex functions which enables us to recover the closed convex envelope of a function from its convex subdifferential. Motivated by this, we introduce the class of Subdifferential Dense Primal Determined (SDPD) spaces, which are those having the necessary condition which allows to use the above integration scheme, and we study several properties of it in the context of Banach spaces. We provide a geometric interpretation of it, called the Faces Radon-Nikod'ym property. In the second part, we study, in the context of Hilbert spaces, the relation between the smoothness of the boundary of a prox-regular set and the smoothness of its metric projection. We show that whenever a set is a closed body with a $mathcal{C}^{p+1}$-smooth boundary (with $pgeq 1$), then its metric projection is of class $mathcal{C}^{p}$ in the open tube associated to its prox-regular function. A local version of the same result is established as well, namely, when the smoothness of the boundary and the prox-regularity of the set are assumed only near a fixed point. We also study the case when the set is itself a $mathcal{C}^{p+1}$-submanifold. Finally, we provide converses for these results
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Mazade, Marc. "Ensembles localement prox-réguliers et inéquations variationnelles." Thesis, Montpellier 2, 2011. http://www.theses.fr/2011MON20141.

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Les propriétés des ensembles localement prox-réguliers ont été étudiées par R.A. Poliquin, R.T. Rockafellar et L. Thibault. Le concept de fonction ''primal lower nice'' a été introduit en dimension finie par R.A. Poliquin et étendu au cadre Hilbertien par A.B. Levy, R.A. Poliquin et L. Thibault. Dans cette thèse, la première partie est consacrée à une étude des outils et des objets géométriques de l'Analyse non lisse tels que les fonctions primal lower nice et les ensembles localement prox-réguliers. On donnera une définition quantifiée de la prox-régularité locale. La deuxième partie établit des résultats d'existence et d'unicité de solutions d'inéquations variationnelles se présentant sous forme d'inclusions différentielles associées au cône normal d'un ensemble localement prox-régulier
The properties of locally prox-regular sets have been studied by R.A. Poliquin, R.T. Rockafellar and L. Thibault. R.A. Poliquin also introduced the concept of ``primal lower nice function. This dissertation is devoted, on one hand to the study of primal lower nice functions and locally prox-regular sets and, on the other hand, to show existence and uniqueness of solutions of differential variational inequalities involwing such sets. Concerning the first part, we introduce a quantified viewpoint of local-prox-regularity and establish a series of characterizations for set satisfying this property. In the second part, we study differential variational inequalities with locally prox-regular sets and we show the relevance of our quantified viewpoint to prove existence results of solutions
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Martins, Anna-Lena. "Local and Global Analysis of Relaxed Douglas-Rachford for Nonconvex Feasibility Problems." Doctoral thesis, 2019. http://hdl.handle.net/21.11130/00-1735-0000-0003-C14C-E.

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Konieczka, Maciej. "Rozpad beta w uogólnionym modelu jądrowego funkcjonału gęstości." Doctoral thesis, 2020. https://depotuw.ceon.pl/handle/item/3735.

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Atomic nuclei form an excellent playground to investigate the primary building blocks of nature in the context of fundamental interactions between particles. Long-range electroma- gnetic Coulomb interaction, short-range strong interaction which binds nucleons into atomic nuclei (nucleon-nucleon interaction), and weak interaction responsible for beta decay pose a serious challenge in theoretical description of the nuclear chart where a deep understanding of all of them is a must. The eld of study is highly interdisciplinary as the understanding of fundamental interactions have been the main goal of the Standard Model of particle physics - the theory which pretends to account for the fundamental laws of nature. Binary structure of atomic nucleus - the quantum system composed of two types of par- ticles protons and neutrons causes the asymmetry of the nucleon-nucleon interaction due to, for instance, electromagnetic interaction which acts only between protons. The analysis of bre- aking of the isospin symmetry in the so-called superallowed Fermi beta decay provides a unique opportunity to verify the basic assumption of the Standard Model, where hadronic structure is built upon three generations of quarks. For that reason one of the key point of the thesis was to focus on the research of unitarity of the Cabbibo-Kobayashi-Maskawa (CKM) quark mixing matrix (Nobel prize 2008 "for the discovery of the origin of the broken symmetry which predicts the existence of at least three families of quarks in nature"). So far, the calculation of nuclear beta decay with an e ective nucleon-nucleon interaction does not contradict with this assumption. Therefore either, we live indeed in the three-generation-quark world or quarks of next generation are so massive that we need much more precise calculation to reach the required level of accuracy of the unitarity of CKM matrix. The Fermi beta decay is by no means the only channel of beta transition. With nearly the same probability the nucleus may decay in the Gamow-Teller channel where the spin change is involved. Many years ago it turned out that the transition probability is systematically overestimated by the theory with respect to experimental data. The observed reduction is re- sponsible for coining the term quenching for the reduction e ect related to the coupling constant of Gamow-Teller type of electroweak currents. The coupling constant has been studied within both nuclear and particle physics. The conclusion that has been made within this work allowed to reject the main hypothesis behind the quenching. Instead of suspecting the drawbacks of the theoretical approach itself it turned out that the solution of the puzzle of the quenching was most probably related to many-body currents, which had been not included at any point in the calculation. Only very recently this statement has been con rmed by the ab initio calculations in several examples of the Gamow-Teller beta decay. Furthermore, the Gamow-Teller transitions are crucial to settle up the research on neutri- noless double beta decay. It is one of the most sought-after process in physics as if measured, would indicate the existence of new physics beyond the Standard Model with neutrino being its own antiparticle with the non-zero mass. The discovery of the neutrino oscillation (Nobel prize 2015) made the subject even more vivid among scientists. It meant that neutrinos are massive. It is therefore obligatory for nuclear theory to perform extremely precise calculation indicating possible isotopes that may decay in that exciting neutrinoless double decay channel. The model that has been widely tested and explored within the thesis, especially in the context of Gamow-Teller transitions, is now almost ready for the calculation of the 0 channel.
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Books on the topic "Regular projections"

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Uwe, Storch, ed. Regular sequences and resultants. Natick, Mass: A.K. Peters, 2001.

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Office, Great Britain War. Canada (warlike stores, &c.): Return to an address of the Honourable the House of Commons, dated 1 May 1872 for, " Returns of all small arms, ordnance, projectiles, ammunition, accoutrements, and all other stores handed over to the government of the Dominion of Canada, in free gift, within three years of the date on which the regular forces were withdrawn from the Upper Provinces of the Dominion, and including the year in which the forces were so withdrawn, with an approximate statement of the value of the different kinds of stores"; "of all other stores transferred on payment to the Government of the Dominion, with an approximate statement of their actual value, and a statement of the amount paid by the government for their stores"; " descriptive statement of all forts and of all other military and other public buildings transferred to the government of the Dominion without payment"; "and, statement of the forts and buildings handed over on payment, with an approximate valuation ...". [London: HMSO, 2002.

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Tom, Fletcher. Book VI Alternative (Including Track 2) Diplomacy, 27 Public Diplomacy and its Offshoots. Oxford University Press, 2016. http://dx.doi.org/10.1093/law/9780198739104.003.0027.

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This chapter discusses public diplomacy, particularly in the context of the digital age. Diplomats now have an increasingly public role to play in projecting their government’s message locally, not just by media appearances and newspaper articles, but by regular use of social media, blogging, Twitter, and evolving techniques. And though technological change has been largely beneficial, the chapter also points to the challenges that technology brings to the field. Diplomats will be part of the debate on our digital rights, tackling the toughest issues around trust and transparency, and helping to find the balance between freedom of expression and the rights of others. Governments will continue to lose their monopoly on information and influence. Secrets will become harder to justify and harder to keep. And in the midst these the role of diplomats is being transformed faster than at any point in history.
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Elliott, Stuart W. Projecting the Impact of Information Technology on Work and Skills in the 2030s. Edited by John Buchanan, David Finegold, Ken Mayhew, and Chris Warhurst. Oxford University Press, 2017. http://dx.doi.org/10.1093/oxfordhb/9780199655366.013.26.

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The research literature in computer science provides a way of understanding the growing capabilities of information technology (IT) and anticipating their future effect on work and skills. This chapter reviews a set of recent computer science articles to identify the IT capabilities that have been demonstrated in research settings. These capabilities are compared to information on occupational ability requirements to identify occupations that are potentially vulnerable to displacement as demonstrated IT capabilities are refined and applied over the next couple decades. The chapter’s preliminary analysis suggests that occupations representing 82 percent of current employment will be potentially vulnerable to displacement by IT in the near future. More rigorous versions of the chapter’s preliminary analysis should be carried out once or twice each decade to track the further development of IT capabilities and regularly update our understanding of their likely consequences for work and skills.
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Scheja, Gunter, and Uwe Storch. Regular Sequences and Resultants: Research Notes in Mathematics, Volume 8 (Research Notes in Mathematics (Boston, Mass.), 8.). AK Peters, 2001.

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Fedyukin, Igor. The Enterprisers. Oxford University Press, 2019. http://dx.doi.org/10.1093/oso/9780190845001.001.0001.

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The Enterprisers traces the emergence of “modern” school in Russia during the reigns of Peter I and his immediate successors, up to the accession of Catherine II. The efforts to “educate” Russia represent a trademark of Peter I’s reign and reformist program, and innovations in schooling in Russia in the eighteenth century have traditionally been presented as a top-down, state-driven process. As with many other facets of the emerging early modern state, the Petrine-era school usually appears as the product of the practical needs of the tsar’s new “regular” army, which demanded skilled technical personnel. It is also commonly taken to be the personal creation of Peter I, who singlehandedly designed it and forced it on an unwilling population. Contrary to this received wisdom, The Enterprisers argues that schools were instead invented and built by “administrative entrepreneurs”—or projecteurs, as they were also called in that era—who sought to achieve diverse career goals, promoted their own pet ideas, advanced their claims for expertise, and competed for status and resources. As the in-depth study of some of the most notable episodes in the history of educational innovation and school-related “projecting” in Russia in the first half of the eighteenth century demonstrates, the creation of “modern” schools took place insofar as it enabled such enterprisers to pursue their agendas. The individual projects these enterprisers proposed and implemented served as building blocks for the edifice of the “well-regulated” state on the threshold of the modern era.
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Book chapters on the topic "Regular projections"

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Díaz-Báñez, José Miguel, Ferran Hurtado, Mario Alberto López, and J. Antoni Sellarès. "Optimal Point Set Projections onto Regular Grids." In Algorithms and Computation, 270–79. Berlin, Heidelberg: Springer Berlin Heidelberg, 2003. http://dx.doi.org/10.1007/978-3-540-24587-2_29.

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Miyazaki, Koji, and Motonaga Ishii. "Symmetry in Projection of 4-Dimensional Regular Polychora." In Complex Symmetries, 43–56. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-88059-0_5.

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Connell, Peter, and Jim Stewart. "Demographic Projections and Population Ageing in Ireland." In The Role of the State in Pension Provision: Employer, Regulator, Provider, 95–111. Boston, MA: Springer US, 1999. http://dx.doi.org/10.1007/978-1-4757-6789-6_11.

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Aasgaard, Rune. "Projecting a Regular Grid onto a Sphere or Ellipsoid." In Advances in Spatial Data Handling, 339–50. Berlin, Heidelberg: Springer Berlin Heidelberg, 2002. http://dx.doi.org/10.1007/978-3-642-56094-1_25.

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England, Matthew, David Wilson, Russell Bradford, and James H. Davenport. "Using the Regular Chains Library to Build Cylindrical Algebraic Decompositions by Projecting and Lifting." In Mathematical Software – ICMS 2014, 458–65. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-662-44199-2_69.

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Dunn, Joseph C. "Augmented Gradient Projection Calculations for Regulator Problems with Pointwise State and Control Constraints." In Applied Optimization, 130–53. Boston, MA: Springer US, 1998. http://dx.doi.org/10.1007/978-1-4757-6095-8_7.

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Shephard, G. C. "PLANE PROJECTIONS OF REGULAR POLYTOPES WITH FIVEFOLD SYMMETRIES." In Fivefold Symmetry, 87–96. WORLD SCIENTIFIC, 1992. http://dx.doi.org/10.1142/9789814439497_0005.

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Sarica, Pinar Yesim. "The Transition of the Pharmaceutical Sector Marketing Activities." In Moving Businesses Online and Embracing E-Commerce, 68–91. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-7998-8294-7.ch004.

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The aim of the study is to understand the change in marketing practices in the pharmaceutical industry in human health during the pandemic process and to reveal the projections for post-marketing strategies in Turkey. With analyzes such as the speed of the industry's adaptation to change, the flexibility of digitalization, the suitability of the existing structure, and the number of employees, future projections have been analyzed on the basis of the evaluations of pharmaceutical sector managers. The environment of the sector that has developed as a result of digitalization has been examined with its positive and negative aspects in terms of employment and employee competencies. As a result, all stakeholders in the pharmaceutical industry are not fully prepared for this process, adapting more slowly than expected in terms of adaptation time. As a living process, the preferences and methods need continuous and regular updating, but it has revealed the fact that digitalization will be passed as a partial and complete final result in its forward-looking predictions.
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"Higher-Dimensional Space of Nanoworld." In Nanotechnologies and Clusters in the Spaces of Higher Dimension, 1–30. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-3784-8.ch001.

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In this chapter, a geometrical model to accurately describe the distribution of light points in diffraction patterns of quasicrystals is proposed. It is shown that the proposed system of parallel lines has axes of the fifth order and periodically repeating the fundamental domain of the quasicrystals. This fundamental domain is 4D-polytope, called the golden hyper-rhombohedron. It consists of eight rhombohedrons densely filling the 4D space. Faces of the hyper-rhombohedron are connected by the golden section; they can be scaled as needed. On this universal lattice of the vertices of the golden hyper-rhombohedrons, famous crystallographic lattices—Bravais, Delone, Voronoi, etc.—can be embedded. On the lattice of the vertices of the golden hyper-rhombohedrons, projections of all regular three-dimensional convex bodies—Plato's bodies—can be constructed.
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Bouchez, Jean-Luc, and Adolphe Nicolas. "Technical aspects of tectonics." In Principles of Rock Deformation and Tectonics, 199–222. Oxford University Press, 2021. http://dx.doi.org/10.1093/oso/9780192843876.003.0010.

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Practical tools that can be useful in tectonic studies are briefly examined in this chapter. Field geologists will find some of these tools to be theoretical and conceptual (e.g., tensors), while a few, such as the universal stage (mounted on an optical microscope), are rarely used in the 21st century. It was routinely employed in the previous century, particularly in crystallography, before the advent of modern (but costly) techniques that use X-rays, neutrons or secondary electrons, which will be also discussed. A good handling of orientation data on 2D-projections (Schmidt or Wulff nets) continues to be very practical and of regular use to geologists. The chapter will end with brief introduction to digital imagery and magnetic studies (Anisotropy of Magnetic Susceptibility, AMS) that help to define shape preferred orientations (SPOs) in rocks, and with gravity techniques that are also commonly in practice in geological studies.
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Conference papers on the topic "Regular projections"

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Jin, Kyung-Chan, Sung-Ho Lee, and Geon-Hee Kim. "Three-Dimensional Tomographic Reconstruction for Microscale Object Modeling." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-51106.

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When scanning a relatively high resolution, thick object using conventional computed tomography (CT), the scanning axis of the X-ray gantry and detector is approximately perpendicular to the rotation axis of the sample. However, the inner interconnections in flat 3D devices are not reconstructed correctly in regular circular CT. In this paper, we focus on 3D tomographic reconstruction of inner interconnections by CT with particular attention to off-centered circular trajectory CT. However, in off-centered circular trajectory CT, the limited tilting angles of projections result in a missing wedge artifact because the object cannot usually be tilted beyond the limit and the data in the remaining projections are not obtained. Therefore, to alleviate missing wedge artifacts, we propose a reconstruction scheme of combining by filtered back projection (FBP) and constraint-based total variation minimization (c-TVM). In the c-TVM method, the artifact of missing wedge is minimized and the reconstructed region is suppressed with high frequency details while leaving the boundaries between homogeneous regions. In our experiments, the CT system obtained the projected images from a rotating sample using a fixed-mounted X-ray source and detector. We acquired 400 rotational projection images of a vertical connection in an off-centered circular trajectory with 30° tilting angles. We then reconstructed the aligned 3D views of the sample. Finally, we demonstrated that the proposed FBP and c-TVM combination with iterative processing yields a superior 3D reconstruction model to conventional tomography.
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Chang, M. P., and O. K. Ersoy. "A new approach for the optimization of digital diffractive optical elements." In OSA Annual Meeting. Washington, D.C.: Optica Publishing Group, 1992. http://dx.doi.org/10.1364/oam.1992.mu3.

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Iterative algorithms such as projections onto constraint sets (POCS) are successful in designing continuous phase structures but have a stagnation problem in designing quantized phase structures. The fewer quantization levels used, the easier the iterations stagnate. The performance of the iterative algorithms can be improved by a number of techniques. An iterative interlacing approach that explores the property of subfields separated in space and combats the residual quantization error stepwise has a superior performance over the regular POCS method. We introduce an extension of this new method, particularly for four levels of phase quantization. Experimental results indicate that this modified iterative interlacing approach reduces the reconstruction error even further compared with a direct quantized phase design. Recent implementations with the e-beam and the reactive ion-etching technologies are also discussed.
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Chua, Kie Hian, Rodney Eatock Taylor, and Yoo Sang Choo. "Hydrodynamics of Side-by-Side Fixed Floating Bodies." In ASME 2016 35th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2016. http://dx.doi.org/10.1115/omae2016-54583.

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Safety of cargo transfer operations between side-by-side vessels depends on accurate modelling of hydrodynamic behavior, especially in terms of predicting the gap free surface elevations between the two vessels. The common industry practice of using linear potential flow models to study these interactions over-predicts the free surface elevations, due to the fact that potential flow does not include viscous dissipation effects such as flow separation at hull corners and skin friction. This may result in inaccurate projections of the time-window when these operations can safely take place. This is an important aspect for developments such as Floating Liquefied Natural Gas (FLNG) platforms, where side-by-side cargo offloading is an essential operation. In a recent research [1], an approach of splitting the amount of energy lost through viscous dissipation (calculated from three-dimensional viscous CFD simulations) into components representative of the flow phenomena has been proposed. Using the approach, referred to as component energy dissipation, the amount of energy lost due to vortex shedding and skin friction can be estimated. Modifications to linear potential flow were also proposed in the referenced research, such that the energy loss components can be converted into dissipative coefficients that are used in terms added to the free surface and body boundary conditions. By combining use of the component energy dissipation approach and the modified dissipative potential flow model, better predictions of gap hydrodynamic interaction can be obtained, compared to using conventional potential flow. In this paper, results from viscous simulations of two identical fixed-floating side-by-side barges of 280m (length) × 46m (breadth) × 16.5m (draught) under excitation from regular incident waves are presented, and compared with corresponding results from the modified dissipative potential flow model. Two types of side-by-side hull configurations were investigated, the first using rectangular barges with sharp bilge corners at varying gap distances and the second using barges with rounded bilge corners of varying radii at a fixed gap distance. Estimation of the dissipative coefficients used in the modified potential flow model, calculated from the viscous results, will also be discussed. The comparison of results serves both as a validation of the modified potential flow model, and to highlight the importance of including viscous dissipation when analyzing hydrodynamic interactions.
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Lin, Xiangli, Caixia Cui, Qing Zhn, Ying Wang, Lefei Wang, Guangcan Yan, Ranran Zhang, Meifang Jing, and Yi Zhao. "Projection Riemannian Manifold based Regular Sparse Array Beamforming for Millimeter Wave Communication." In 2023 IEEE 97th Vehicular Technology Conference (VTC2023-Spring). IEEE, 2023. http://dx.doi.org/10.1109/vtc2023-spring57618.2023.10200832.

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Meziane, B. "Degenerate Period Doubling Route to Chaos in the Casperson-Instability Simplified Model." In Nonlinear Dynamics in Optical Systems. Washington, D.C.: Optica Publishing Group, 1990. http://dx.doi.org/10.1364/nldos.1990.oc519.

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A low-dimensional model of the "Casperson Instability" showing regular self-pulsing behavior in the 4D space is presented. The projection on to the 3D subspace exhibits period doubling bifurcations to chaos with increasing the level of excitation.
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Meng, Li, Yao Guoqing, Cai Hongyue, Wang Haoyu, and Ju Hengzhe. "Joint Statistics on Stereographic Projection of Contour Creating Algorithm Based on Regular Grid Data." In 2014 7th International Symposium on Computational Intelligence and Design (ISCID). IEEE, 2014. http://dx.doi.org/10.1109/iscid.2014.256.

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Obinata, Yuya, Genta Suzuki, Taichi Murase, and Yusaku Fujii. "Pose Estimation for a Cuboid with Regular Patterns in an Interactive Assembly-support Projection System." In ISS '16: 2016 ACM International Conference on Interactive Surfaces and Spaces. New York, NY, USA: ACM, 2016. http://dx.doi.org/10.1145/2992154.2996776.

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Pavlov, Andrei Valerianovich. "Reflection of Functions and Linear Prognosis." In International Research-to-practice conference. TSNS Interaktiv Plus, 2021. http://dx.doi.org/10.21661/r-553927.

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Periodicity of wide class of functions as a result of reflection of even and arbitrary regular functions is proved. By consideration of new scalar work in space of linear shell of initial n vectors the equivalence of values of two different scalar productions is proved. The example of linear transformation is considered on plane for the symmetric case, resulting in possibility to make to use the orthogonal sides of rhombus at projection on the plane of its parties.
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Ahuja, J., S. Tiwari, and A. Kumar. "Numerical investigation of shock-induced combustion past blunt projectiles in regular and large-disturbance regimes." In 33rd Aerospace Sciences Meeting and Exhibit. Reston, Virigina: American Institute of Aeronautics and Astronautics, 1995. http://dx.doi.org/10.2514/6.1995-153.

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Craeye, Christophe, David Gonzalez-Ovejero, Nima Razavi Ghods, and Eloy de Lera Acedo. "A projection approach to model the main beam of non-regular arrays in presence of mutual coupling." In 2012 6th European Conference on Antennas and Propagation (EuCAP). IEEE, 2012. http://dx.doi.org/10.1109/eucap.2012.6206157.

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Reports on the topic "Regular projections"

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Hubbard, Sarah M., and Bryan Hubbard. Investigation of Strategic Deployment Opportunities for Unmanned Aerial Systems (UAS) at INDOT. Purdue University, 2020. http://dx.doi.org/10.5703/1288284317126.

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Unmanned aerial systems (UAS) are increasingly used for a variety of applications related to INDOT’s mission including bridge inspection, traffic management, incident response, construction and roadway mapping. UAS have the potential to reduce costs and increase capabilities. Other state DOTs and transportation agencies have deployed UAS for an increasing number of applications due to technology advances that provide increased capabilities and lower costs, resulting from regulatory changes that simplified operations for small UAS under 55 pounds (aka, sUAS). This document provides an overview of UAS applications that may be appropriate for INDOT, as well as a description of the regulations that affect UAS operation as described in 14 CFR Part 107. The potential applications were prioritized using Quality Function Deployment (QFD), a methodology used in the aerospace industry that clearly communicates qualitative and ambiguous information with a transparent framework for decision making. The factors considered included technical feasibility, ease of adoption and stakeholder acceptance, activities underway at INDOT, and contribution to INDOT mission and goals. Dozens of interviews with INDOT personnel and stakeholders were held to get an accurate and varied perspective of potential for UAVs at INDOT. The initial prioritization was completed in early 2019 and identified three key areas: UAS for bridge inspection safety as a part of regular operations, UAS for construction with deliverables provided via construction contracts, and UAS for emergency management. Descriptions of current practices and opportunities for INDOT are provided for each of these applications. An estimate of the benefits and costs is identified, based on findings from other agencies as well as projections for INDOT. A benefit cost analysis for the application of UAS for bridge inspection safety suggests a benefit cost over one for the analysis period.
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Rukundo, Solomon. Tax Amnesties in Africa: An Analysis of the Voluntary Disclosure Programme in Uganda. Institute of Development Studies (IDS), December 2020. http://dx.doi.org/10.19088/ictd.2020.005.

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Tax amnesties have taken centre stage as a compliance tool in recent years. The OECD estimates that since 2009 tax amnesties in 40 jurisdictions have resulted in the collection of an additional €102 billion in tax revenue. A number of African countries have introduced tax amnesties in the last decade, including Nigeria, Namibia, South Africa and Tanzania. Despite their global popularity, the efficacy of tax amnesties as a tax compliance tool remains in doubt. The revenue is often below expectations, and it probably could have been raised through effective use of regular enforcement measures. It is also argued that tax amnesties might incentivise non-compliance – taxpayers may engage in non-compliance in the hope of benefiting from an amnesty. This paper examines the administration of tax amnesties in various jurisdictions around the world, including the United States, Australia, Canada, Kenya and South Africa. The paper makes a cost-benefit analysis of these and other tax amnesties – and from this analysis develops a model tax amnesty, whose features maximise the benefits of a tax amnesty while minimising the potential costs. The model tax amnesty: (1) is permanent, (2) is available only to taxpayers who make a voluntary disclosure, (3) relieves taxpayers of penalties, interest and the risk of prosecution, but treats intentional and unintentional non-compliance differently, (4) has clear reporting requirements for taxpayers, and (5) is communicated clearly to attract non-compliant taxpayers without appearing unfair to the compliant ones. The paper then focuses on the Ugandan tax amnesty introduced in July 2019 – a Voluntary Disclosure Programme (VDP). As at 7 November 2020, this initiative had raised USh16.8 billion (US$6.2 million) against a projection of USh45 billion (US$16.6 million). The paper examines the legal regime and administration of this VDP, scoring it against the model tax amnesty. It notes that, while the Ugandan VDP partially matches up to the model tax amnesty, because it is permanent, restricted to taxpayers who make voluntary disclosure and relieves penalties and interest only, it still falls short due to a number of limitations. These include: (1) communication of the administration of the VDP through a public notice, instead of a practice note that is binding on the tax authority; (2) uncertainty regarding situations where a VDP application is made while the tax authority has been doing a secret investigation into the taxpayer’s affairs; (3) the absence of differentiated treatment between taxpayers involved in intentional non-compliance, and those whose non-compliance may be unintentional; (4) lack of clarity on how the VDP protects the taxpayer when non-compliance involves the breach of other non-tax statutes, such as those governing financial regulation; (5)absence of clear timelines in the administration of the VDP, which creates uncertainty;(6)failure to cater for voluntary disclosures with minor errors; (7) lack of clarity on VDP applications that result in a refund position for the applicant; and (8) lack of clarity on how often a VDP application can be made. The paper offers recommendations on how the Ugandan VDP can be aligned to match the model tax amnesty, in order to gain the most from this compliance tool.
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