From Golden Spirals to Constant Slope Surfaces
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Engineering Curves – I
Engineering Curves – I 1. Classification 2. Conic sections - explanation 3. Common Definition 4. Ellipse – ( six methods of construction) 5. Parabola – ( Three methods of construction) 6. Hyperbola – ( Three methods of construction ) 7. Methods of drawing Tangents & Normals ( four cases) Engineering Curves – II 1. Classification 2. Definitions 3. Involutes - (five cases) 4. Cycloid 5. Trochoids – (Superior and Inferior) 6. Epic cycloid and Hypo - cycloid 7. Spiral (Two cases) 8. Helix – on cylinder & on cone 9. Methods of drawing Tangents and Normals (Three cases) ENGINEERING CURVES Part- I {Conic Sections} ELLIPSE PARABOLA HYPERBOLA 1.Concentric Circle Method 1.Rectangle Method 1.Rectangular Hyperbola (coordinates given) 2.Rectangle Method 2 Method of Tangents ( Triangle Method) 2 Rectangular Hyperbola 3.Oblong Method (P-V diagram - Equation given) 3.Basic Locus Method 4.Arcs of Circle Method (Directrix – focus) 3.Basic Locus Method (Directrix – focus) 5.Rhombus Metho 6.Basic Locus Method Methods of Drawing (Directrix – focus) Tangents & Normals To These Curves. CONIC SECTIONS ELLIPSE, PARABOLA AND HYPERBOLA ARE CALLED CONIC SECTIONS BECAUSE THESE CURVES APPEAR ON THE SURFACE OF A CONE WHEN IT IS CUT BY SOME TYPICAL CUTTING PLANES. OBSERVE ILLUSTRATIONS GIVEN BELOW.. Ellipse Section Plane Section Plane Hyperbola Through Generators Parallel to Axis. Section Plane Parallel to end generator. COMMON DEFINATION OF ELLIPSE, PARABOLA & HYPERBOLA: These are the loci of points moving in a plane such that the ratio of it’s distances from a fixed point And a fixed line always remains constant. The Ratio is called ECCENTRICITY. (E) A) For Ellipse E<1 B) For Parabola E=1 C) For Hyperbola E>1 Refer Problem nos. -
A Characterization of Helical Polynomial Curves of Any Degree
A CHARACTERIZATION OF HELICAL POLYNOMIAL CURVES OF ANY DEGREE J. MONTERDE Abstract. We give a full characterization of helical polynomial curves of any degree and a simple way to construct them. Existing results about Hermite interpolation are revisited. A simple method to select the best quintic interpolant among all possible solutions is suggested. 1. Introduction The notion of helical polynomial curves, i.e, polynomial curves which made a constant angle with a ¯xed line in space, have been studied by di®erent authors. Let us cite the papers [5, 6, 7] where the main results about the cubical and quintic cases are stablished. In [5] the authors gives a necessary condition a polynomial curve must satisfy in order to be a helix. The condition is expressed in terms of its hodograph, i.e., its derivative. If a polynomial curve, ®, is a helix then its hodograph, ®0, must be Pythagorean, i.e., jj®0jj2 is a perfect square of a polynomial. Moreover, this condition is su±cient in the cubical case: all PH cubical curves are helices. In the same paper it is also stated that not only ®0 must be Pythagorean, but also ®0^®00. Following the same ideas, in [1] it is proved that both conditions are su±cient in the quintic case. Unfortunately, this characterization is no longer true for higher degrees. It is possible to construct examples of polynomial curves of degree 7 verifying both conditions but being not a helix. The aim of this paper is just to show how a simple geometric trick can clarify the proofs of some previous results and to simplify the needed compu- tations to solve some related problems as for instance, the Hermite problem using helical polynomial curves. -
Linguistic Presentation of Objects
Zygmunt Ryznar dr emeritus Cracow Poland [email protected] Linguistic presentation of objects (types,structures,relations) Abstract Paper presents phrases for object specification in terms of structure, relations and dynamics. An applied notation provides a very concise (less words more contents) description of object. Keywords object relations, role, object type, object dynamics, geometric presentation Introduction This paper is based on OSL (Object Specification Language) [3] dedicated to present the various structures of objects, their relations and dynamics (events, actions and processes). Jay W.Forrester author of fundamental work "Industrial Dynamics”[4] considers the importance of relations: “the structure of interconnections and the interactions are often far more important than the parts of system”. Notation <!...> comment < > container of (phrase,name...) ≡> link to something external (outside of definition)) <def > </def> start-end of definition <spec> </spec> start-end of specification <beg> <end> start-end of section [..] or {..} 1 list of assigned keywords :[ or :{ structure ^<name> optional item (..) list of items xxxx(..) name of list = value assignment @ mark of special attribute,feature,property @dark unknown, to obtain, to discover :: belongs to : equivalent name (e.g.shortname) # number of |name| executive/operational object ppppXxxx name of item Xxxx with prefix ‘pppp ‘ XXXX basic object UUUU.xxxx xxxx object belonged to UUUU object class & / conjunctions ‘and’ ‘or’ 1 If using Latex editor we suggest [..] brackets -
Helical Curves and Double Pythagorean Hodographs
Helical polynomial curves and “double” Pythagorean-hodograph curves Rida T. Farouki Department of Mechanical & Aeronautical Engineering, University of California, Davis — synopsis — • introduction: properties of Pythagorean-hodograph curves • computing rotation-minimizing frames on spatial PH curves • helical polynomial space curves — are always PH curves • standard quaternion representation for spatial PH curves • “double” Pythagorean hodograph structure — requires both |r0(t)| and |r0(t) × r00(t)| to be polynomials in t • Hermite interpolation problem: selection of free parameters Pythagorean-hodograph (PH) curves r(ξ) = PH curve ⇐⇒ coordinate components of r0(ξ) comprise a “Pythagorean n-tuple of polynomials” in Rn PH curves incorporate special algebraic structures in their hodographs (complex number & quaternion models for planar & spatial PH curves) • rational offset curves rd(ξ) = r(ξ) + d n(ξ) Z ξ • polynomial arc-length function s(ξ) = |r0(ξ)| dξ 0 Z 1 • closed-form evaluation of energy integral E = κ2 ds 0 • real-time CNC interpolators, rotation-minimizing frames, etc. helical polynomial space curves several equivalent characterizations of helical curves • tangent t maintains constant inclination ψ with fixed vector a • a · t = cos ψ, where ψ = pitch angle and a = axis vector of helix • fixed curvature/torsion ratio, κ/τ = tan ψ (Theorem of Lancret) • curve has a circular tangent indicatrix on the unit sphere (small circle for space curve, great circle for planar curve) • (r(2) × r(3)) · r(4) ≡ 0 — where r(k) = kth arc–length derivative -
Golden Ratio: a Subtle Regulator in Our Body and Cardiovascular System?
See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/306051060 Golden Ratio: A subtle regulator in our body and cardiovascular system? Article in International journal of cardiology · August 2016 DOI: 10.1016/j.ijcard.2016.08.147 CITATIONS READS 8 266 3 authors, including: Selcuk Ozturk Ertan Yetkin Ankara University Istinye University, LIV Hospital 56 PUBLICATIONS 121 CITATIONS 227 PUBLICATIONS 3,259 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: microbiology View project golden ratio View project All content following this page was uploaded by Ertan Yetkin on 23 August 2019. The user has requested enhancement of the downloaded file. International Journal of Cardiology 223 (2016) 143–145 Contents lists available at ScienceDirect International Journal of Cardiology journal homepage: www.elsevier.com/locate/ijcard Review Golden ratio: A subtle regulator in our body and cardiovascular system? Selcuk Ozturk a, Kenan Yalta b, Ertan Yetkin c,⁎ a Abant Izzet Baysal University, Faculty of Medicine, Department of Cardiology, Bolu, Turkey b Trakya University, Faculty of Medicine, Department of Cardiology, Edirne, Turkey c Yenisehir Hospital, Division of Cardiology, Mersin, Turkey article info abstract Article history: Golden ratio, which is an irrational number and also named as the Greek letter Phi (φ), is defined as the ratio be- Received 13 July 2016 tween two lines of unequal length, where the ratio of the lengths of the shorter to the longer is the same as the Accepted 7 August 2016 ratio between the lengths of the longer and the sum of the lengths. -
Chapter 2. Parameterized Curves in R3
Chapter 2. Parameterized Curves in R3 Def. A smooth curve in R3 is a smooth map σ :(a, b) → R3. For each t ∈ (a, b), σ(t) ∈ R3. As t increases from a to b, σ(t) traces out a curve in R3. In terms of components, σ(t) = (x(t), y(t), z(t)) , (1) or x = x(t) σ : y = y(t) a < t < b , z = z(t) dσ velocity at time t: (t) = σ0(t) = (x0(t), y0(t), z0(t)) . dt dσ speed at time t: (t) = |σ0(t)| dt Ex. σ : R → R3, σ(t) = (r cos t, r sin t, 0) - the standard parameterization of the unit circle, x = r cos t σ : y = r sin t z = 0 σ0(t) = (−r sin t, r cos t, 0) |σ0(t)| = r (constant speed) 1 Ex. σ : R → R3, σ(t) = (r cos t, r sin t, ht), r, h > 0 constants (helix). σ0(t) = (−r sin t, r cos t, h) √ |σ0(t)| = r2 + h2 (constant) Def A regular curve in R3 is a smooth curve σ :(a, b) → R3 such that σ0(t) 6= 0 for all t ∈ (a, b). That is, a regular curve is a smooth curve with everywhere nonzero velocity. Ex. Examples above are regular. Ex. σ : R → R3, σ(t) = (t3, t2, 0). σ is smooth, but not regular: σ0(t) = (3t2, 2t, 0) , σ0(0) = (0, 0, 0) Graph: x = t3 y = t2 = (x1/3)2 σ : y = t2 ⇒ y = x2/3 z = 0 There is a cusp, not because the curve isn’t smooth, but because the velocity = 0 at the origin. -
Linguistic Presentation of Object Structure and Relations in OSL Language
Zygmunt Ryznar Linguistic presentation of object structure and relations in OSL language Abstract OSL© is a markup descriptive language for the description of any object in terms of structure and behavior. In this paper we present a geometric approach, the kernel and subsets for IT system, business and human-being as a proof of universality. This language was invented as a tool for a free structured modeling and design. Keywords free structured modeling and design, OSL, object specification language, human descriptive language, factual markup, geometric view, object specification, GSO -geometrically structured objects. I. INTRODUCTION Generally, a free structured modeling is a collection of methods, techniques and tools for modeling the variable structure as an opposite to the widely used “well-structured” approach focused on top-down hierarchical decomposition. It is assumed that system boundaries are not finally defined, because the system is never to be completed and components are are ready to be modified at any time. OSL is dedicated to present the various structures of objects, their relations and dynamics (events, actions and processes). This language may be counted among markup languages. The fundamentals of markup languages were created in SGML (Standard Generalized Markup Language) [6] descended from GML (name comes from first letters of surnames of authors: Goldfarb, Mosher, Lorie, later renamed as Generalized Markup Language) developed at IBM [15]. Markups are usually focused on: - documents (tags: title, abstract, keywords, menu, footnote etc.) e.g. latex [14], - objects (e.g. OSL), - internet pages (tags used in html, xml – based on SGML [8] rules), - data (e.g. structured data markup: microdata, microformat, RFDa [13],YAML [12]). -
The Golden Ratio
Mathematical Puzzle Sessions Cornell University, Spring 2012 1 Φ: The Golden Ratio p 1 + 5 The golden ratio is the number Φ = ≈ 1:618033989. (The greek letter Φ used to 2 represent this number is pronounced \fee".) Where does the number Φ come from? Suppose a line is broken into two pieces, one of length a and the other of length b (so the total length is a + b), and a and b are chosen in a very specific way: a and b are chosen so that the ratio of a + b to a and the ratio of a to b are equal. a b a + b a ! a b a+b a It turns out that if a and b satisfy this property so that a = b then the ratios are equal to the number Φ! It is called the golden ratio because among the ancient Greeks it was thought that this ratio is the most pleasing to the eye. a Try This! You can verify that if the two ratios are equal then b = Φ yourself with a bit of careful algebra. Let a = 1 and use the quadratic equation to find the value of b that makes 1 the two ratios equal. If you successfully worked out the value of b you should find b = Φ. The Golden Rectangle A rectangle is called a golden rectangle if the ratio of the sides of the rectangle is equal to Φ, like the one shown below. 1 Φ p 1 −1+ 5 If the ratio of the sides is Φ = 2 this is also considered a golden rectangle. -
Geometry and Art & Architecture
CHARACTERISTICS AND INTERRELATIONS OF FORMS ARCH 115 Instructor: F. Oya KUYUMCU Mathematics in Architecture • Mathematics can, broadly speaking, be subdivided into to study of quantity - arithmetic structure – algebra space – geometry and change – analysis. In addition to these main concerns, there are also sub-divisions dedicated to exploring links from the heart of mathematics to other field. to logic, to set theory (foundations) to the empirical mathematics of the various sciences to the rigorous study of uncertanity Lecture Topics . Mathematics and Architecture are wholly related with each other. All architectural products from the door to the building cover a place in space. So, all architectural elements have a volume. One of the study field of mathematics, name is geometry is totally concern this kind of various dimensional forms such as two or three or four. If you know geometry well, you can create true shapes and forms for architecture. For this reason, in this course, first we’ll look to the field of geometry especially two and three dimensions. Our second goal will be learning construction (drawing) of this two or three dimensional forms. • Architects intentionally or accidently use ratio and mathematical proportions to shape buildings. So, our third goal will be learning some mathematical concepts like ratio and proportions. • In this course, we explore the many places where the fields of art, architecture and mathematics. For this aim, we’ll try to learn concepts related to these fields like tetractys, magic squares, fractals, penrose tilling, cosmic rythms etc. • We will expose to you to wide range of art covering a long historical period and great variety of styles from the Egyptians up to contemporary world of art and architecture. -
On Helices and Bertrand Curves in Euclidean 3-Space
ON HELİCES AND BERTRAND CURVES IN EUCLİDEAN 3-SPACE Murat Babaarslan Department of Mathematics, Faculty of Science and Arts Bozok University, Yozgat, Turkey [email protected] Yusuf Yaylı Department of Mathematics, Faculty of Science Ankara University, Tandoğan, Ankara, Turkey [email protected] Abstract- In this article, we investigate Bertrand curves corresponding to spherical images of the tangent indicatrix, binormal indicatrix, principal normal indicatrix and Darboux indicatrix of a space curve in Euclidean 3-space. As a result, in case of a space curve is general helix, we show that curve corresponding to spherical images of its tangent indicatrix and binormal indicatrix are circular helices and Bertrand curves. Similarly, in case of a space curve is slant helix, we demonstrate that the curve corresponding to spherical image of its principal normal indicatrix is circular helix and Bertrand curve. Key Words- Helix, Bertrand curve, Spherical Images 1. INTRODUCTION In the differential geometry of a regular curve in Euclidean 3-space E3 , it is well known that, one of the important problems is characterization of a regular curve. The curvature and the torsion of a regular curve play an important role to determine the shape and size of the curve 1,2. Natural scientists have long held a fascination, sometimes bordering on mystical obsession for helical structures in nature. Helices arise in nanosprings, carbon nonotubes, helices, DNA double and collagen triple helix, the double helix shape is commonly associated with DNA, since the double helix is structure of DNA 3 . This fact was published for the first time by Watson and Crick in 1953 4. -
A Note on Unbounded Apollonian Disk Packings
A note on unbounded Apollonian disk packings Jerzy Kocik Department of Mathematics Southern Illinois University, Carbondale, IL62901 [email protected] (version 6 Jan 2019) Abstract A construction and algebraic characterization of two unbounded Apollonian Disk packings in the plane and the half-plane are presented. Both turn out to involve the golden ratio. Keywords: Unbounded Apollonian disk packing, golden ratio, Descartes configuration, Kepler’s triangle. 1 Introduction We present two examples of unbounded Apollonian disk packings, one that fills a half-plane and one that fills the whole plane (see Figures 3 and 7). Quite interestingly, both are related to the golden ratio. We start with a brief review of Apollonian disk packings, define “unbounded”, and fix notation and terminology. 14 14 6 6 11 3 11 949 9 4 9 2 2 1 1 1 11 11 arXiv:1910.05924v1 [math.MG] 14 Oct 2019 6 3 6 949 9 4 9 14 14 Figure 1: Apollonian Window (left) and Apollonian Belt (right). The Apollonian disk packing is a fractal arrangement of disks such that any of its three mutually tangent disks determine it by recursivly inscribing new disks in the curvy-triangular spaces that emerge between the disks. In such a context, the three initial disks are called a seed of the packing. Figure 1 shows for two most popular examples: the “Apollonian Window” and the “Apollonian Belt”. The num- bers inside the circles represent their curvatures (reciprocals of the radii). Note that the curvatures are integers; such arrangements are called integral Apollonian disk pack- ings; they are classified and their properties are still studied [3, 5, 6]. -
The Golden Relationships: an Exploration of Fibonacci Numbers and Phi
The Golden Relationships: An Exploration of Fibonacci Numbers and Phi Anthony Rayvon Watson Faculty Advisor: Paul Manos Duke University Biology Department April, 2017 This project was submitted in partial fulfillment of the requirements for the degree of Master of Arts in the Graduate Liberal Studies Program in the Graduate School of Duke University. Copyright by Anthony Rayvon Watson 2017 Abstract The Greek letter Ø (Phi), represents one of the most mysterious numbers (1.618…) known to humankind. Historical reverence for Ø led to the monikers “The Golden Number” or “The Devine Proportion”. This simple, yet enigmatic number, is inseparably linked to the recursive mathematical sequence that produces Fibonacci numbers. Fibonacci numbers have fascinated and perplexed scholars, scientists, and the general public since they were first identified by Leonardo Fibonacci in his seminal work Liber Abacci in 1202. These transcendent numbers which are inextricably bound to the Golden Number, seemingly touch every aspect of plant, animal, and human existence. The most puzzling aspect of these numbers resides in their universal nature and our inability to explain their pervasiveness. An understanding of these numbers is often clouded by those who seemingly find Fibonacci or Golden Number associations in everything that exists. Indeed, undeniable relationships do exist; however, some represent aspirant thinking from the observer’s perspective. My work explores a number of cases where these relationships appear to exist and offers scholarly sources that either support or refute the claims. By analyzing research relating to biology, art, architecture, and other contrasting subject areas, I paint a broad picture illustrating the extensive nature of these numbers.