Encyclopedia of Analytical Surfaces S.N
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Brief Information on the Surfaces Not Included in the Basic Content of the Encyclopedia
Brief Information on the Surfaces Not Included in the Basic Content of the Encyclopedia Brief information on some classes of the surfaces which cylinders, cones and ortoid ruled surfaces with a constant were not picked out into the special section in the encyclo- distribution parameter possess this property. Other properties pedia is presented at the part “Surfaces”, where rather known of these surfaces are considered as well. groups of the surfaces are given. It is known, that the Plücker conoid carries two-para- At this section, the less known surfaces are noted. For metrical family of ellipses. The straight lines, perpendicular some reason or other, the authors could not look through to the planes of these ellipses and passing through their some primary sources and that is why these surfaces were centers, form the right congruence which is an algebraic not included in the basic contents of the encyclopedia. In the congruence of the4th order of the 2nd class. This congru- basis contents of the book, the authors did not include the ence attracted attention of D. Palman [8] who studied its surfaces that are very interesting with mathematical point of properties. Taking into account, that on the Plücker conoid, view but having pure cognitive interest and imagined with ∞2 of conic cross-sections are disposed, O. Bottema [9] difficultly in real engineering and architectural structures. examined the congruence of the normals to the planes of Non-orientable surfaces may be represented as kinematics these conic cross-sections passed through their centers and surfaces with ruled or curvilinear generatrixes and may be prescribed a number of the properties of a congruence of given on a picture. -
Parametric Modelling of Architectural Developables Roel Van De Straat Scientific Research Mentor: Dr
MSc thesis: Computation & Performance parametric modelling of architectural developables Roel van de Straat scientific research mentor: dr. ir. R.M.F. Stouffs design research mentor: ir. F. Heinzelmann third mentor: ir. J.L. Coenders Computation & Performance parametric modelling of architectural developables MSc thesis: Computation & Performance parametric modelling of architectural developables Roel van de Straat 1041266 Delft, April 2011 Delft University of Technology Faculty of Architecture Computation & Performance parametric modelling of architectural developables preface The idea of deriving analytical and structural information from geometrical complex design with relative simple design tools was one that was at the base of defining the research question during the early phases of the graduation period, starting in September of 2009. Ultimately, the research focussed an approach actually reversely to this initial idea by concentrating on using analytical and structural logic to inform the design process with the aid of digital design tools. Generally, defining architectural characteristics with an analytical approach is of increasing interest and importance with the emergence of more complex shapes in the building industry. This also means that embedding structural, manufacturing and construction aspects early on in the design process is of interest. This interest largely relates to notions of surface rationalisation and a design approach with which initial design sketches can be transferred to rationalised designs which focus on a strong integration with manufacturability and constructability. In order to exemplify this, the design of the Chesa Futura in Sankt Moritz, Switzerland by Foster and Partners is discussed. From the initial design sketch, there were many possible approaches for surfacing techniques defining the seemingly freeform design. -
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 -
Semiflexible Polymers
Semiflexible Polymers: Fundamental Theory and Applications in DNA Packaging Thesis by Andrew James Spakowitz In Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy California Institute of Technology MC 210-41 Caltech Pasadena, California 91125 2004 (Defended September 28, 2004) ii c 2004 Andrew James Spakowitz All Rights Reserved iii Acknowledgements Over the last five years, I have benefitted greatly from my interactions with many people in the Caltech community. I am particularly grateful to the members of my thesis committee: John Brady, Rob Phillips, Niles Pierce, and David Tirrell. Their example has served as guidance in my scientific development, and their professional assistance and coaching have proven to be invaluable in my future career plans. Our collaboration has impacted my research in many ways and will continue to be fruitful for years to come. I am grateful to my research advisor, Zhen-Gang Wang. Throughout my scientific development, Zhen-Gang’s ongoing patience and honesty have been instrumental in my scientific growth. As a researcher, his curiosity and fearlessness have been inspirational in developing my approach and philosophy. As an advisor, he serves as a model that I will turn to throughout the rest of my career. Throughout my life, my family’s love, encouragement, and understanding have been of utmost importance in my development, and I thank them for their ongoing devotion. My friends have provided the support and, at times, distraction that are necessary in maintaining my sanity; for this, I am thankful. Finally, I am thankful to my fianc´ee, Sarah Heilshorn, for her love, support, encourage- ment, honesty, critique, devotion, and wisdom. -
Title CLAD HELICES and DEVELOPABLE SURFACES( Fulltext )
CLAD HELICES AND DEVELOPABLE SURFACES( Title fulltext ) Author(s) TAKAHASHI,Takeshi; TAKEUCHI,Nobuko Citation 東京学芸大学紀要. 自然科学系, 66: 1-9 Issue Date 2014-09-30 URL http://hdl.handle.net/2309/136938 Publisher 東京学芸大学学術情報委員会 Rights Bulletin of Tokyo Gakugei University, Division of Natural Sciences, 66: pp.1~ 9 ,2014 CLAD HELICES AND DEVELOPABLE SURFACES Takeshi TAKAHASHI* and Nobuko TAKEUCHI** Department of Mathematics (Received for Publication; May 23, 2014) TAKAHASHI, T and TAKEUCHI, N.: Clad Helices and Developable Surfaces. Bull. Tokyo Gakugei Univ. Div. Nat. Sci., 66: 1-9 (2014) ISSN 1880-4330 Abstract We define new special curves in Euclidean 3-space which are generalizations of the notion of helices. Then we find a geometric invariant of a space curve which is related to the singularities of the special developable surface of the original curve. Keywords: cylindrical helices, slant helices, clad helices, g-clad helices, developable surfaces, singularities Department of Mathematics, Tokyo Gakugei University, 4-1-1 Nukuikita-machi, Koganei-shi, Tokyo 184-8501, Japan 1. Introduction In this paper we define the notion of clad helices and g-clad helices which are generalizations of the notion of helices. Then we can find them as geodesics on the tangent developable(cf., §3). In §2 we describe basic notions and properties of space curves. We review the classification of singularities of the Darboux developable of a space curve in §4. We introduce the notion of the principal normal Darboux developable of a space curve. Then we find a geometric invariant of a clad helix which is related to the singularities of the principal normal Darboux developable of the original curve. -
Exploring Locus Surfaces Involving Pseudo Antipodal Points
Proceedings of the 25th Asian Technology Conference in Mathematics Exploring Locus Surfaces Involving Pseudo Antipodal Points Wei-Chi YANG [email protected] Department of Mathematics and Statistics Radford University Radford, VA 24142 USA Abstract The discussions in this paper were inspired by a college entrance practice exam from China. It is extended to investigate the locus curve that involves a point on an ellipse and its pseudo antipodal point with respect to a xed point. With the help of technological tools, we explore 2D locus for some regular closed curves. Later, we investigate how a locus curve can be extended to the corresponding 3D locus surfaces on surfaces like ellipsoid, cardioidal surface and etc. Secondly, we use the de nition of a developable surface (including tangent developable surface) to construct the corresponding locus surface. It is well known that, in robotics, antipodal grasps can be achieved on curved objects. In addition, there are many applications already in engineering and architecture about the developable surfaces. We hope the discussions regarding the locus surfaces can inspire further interesting research in these areas. 1 Introduction Technological tools have in uenced our learning, teaching and research in mathematics in many di erent ways. In this paper, we start with a simple exam problem and with the help of tech- nological tools, we are able to turn the problem into several challenging problems in 2D and 3D. The visualization bene ted from exploration provides us crucial intuition of how we can analyze our solutions with a computer algebra system. Therefore, while implementing techno- logical tools to allow exploration in our curriculum is de nitely a must. -
Some Curves and the Lengths of Their Arcs Amelia Carolina Sparavigna
Some Curves and the Lengths of their Arcs Amelia Carolina Sparavigna To cite this version: Amelia Carolina Sparavigna. Some Curves and the Lengths of their Arcs. 2021. hal-03236909 HAL Id: hal-03236909 https://hal.archives-ouvertes.fr/hal-03236909 Preprint submitted on 26 May 2021 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Some Curves and the Lengths of their Arcs Amelia Carolina Sparavigna Department of Applied Science and Technology Politecnico di Torino Here we consider some problems from the Finkel's solution book, concerning the length of curves. The curves are Cissoid of Diocles, Conchoid of Nicomedes, Lemniscate of Bernoulli, Versiera of Agnesi, Limaçon, Quadratrix, Spiral of Archimedes, Reciprocal or Hyperbolic spiral, the Lituus, Logarithmic spiral, Curve of Pursuit, a curve on the cone and the Loxodrome. The Versiera will be discussed in detail and the link of its name to the Versine function. Torino, 2 May 2021, DOI: 10.5281/zenodo.4732881 Here we consider some of the problems propose in the Finkel's solution book, having the full title: A mathematical solution book containing systematic solutions of many of the most difficult problems, Taken from the Leading Authors on Arithmetic and Algebra, Many Problems and Solutions from Geometry, Trigonometry and Calculus, Many Problems and Solutions from the Leading Mathematical Journals of the United States, and Many Original Problems and Solutions. -
Spiral Pdf, Epub, Ebook
SPIRAL PDF, EPUB, EBOOK Roderick Gordon,Brian Williams | 496 pages | 01 Sep 2011 | Chicken House Ltd | 9781906427849 | English | Somerset, United Kingdom Spiral PDF Book Clear your history. Cann is on the run. Remark: a rhumb line is not a spherical spiral in this sense. The spiral has inspired artists throughout the ages. Metacritic Reviews. Fast, Simple and effective in getting high quality formative assessment in seconds. It has been nominated at the Globes de Cristal Awards four times, winning once. Name that government! This last season has two episodes less than the previous ones. The loxodrome has an infinite number of revolutions , with the separation between them decreasing as the curve approaches either of the poles, unlike an Archimedean spiral which maintains uniform line-spacing regardless of radius. Ali Tewfik Jellab changes from recurring character to main. William Schenk Christopher Tai Looking for a movie the entire family can enjoy? Looking for a movie the entire family can enjoy? Edit Cast Series cast summary: Caroline Proust June Assess in real-time or asynchronously. Time Traveler for spiral The first known use of spiral was in See more words from the same year. A hyperbolic spiral appears as image of a helix with a special central projection see diagram. TV series to watch. External Sites. That dark, messy, morally ambivalent universe they live in is recognisable even past the cultural differences, such as the astonishing blurring of the boundary between investigative police work and judgement — it's not so much uniquely French as uniquely modern. Photo Gallery. Some familiar faces, and some new characters, keep things ticking along nicely. -
Archimedean Spirals ∗
Archimedean Spirals ∗ An Archimedean Spiral is a curve defined by a polar equation of the form r = θa, with special names being given for certain values of a. For example if a = 1, so r = θ, then it is called Archimedes’ Spiral. Archimede’s Spiral For a = −1, so r = 1/θ, we get the reciprocal (or hyperbolic) spiral. Reciprocal Spiral ∗This file is from the 3D-XploreMath project. You can find it on the web by searching the name. 1 √ The case a = 1/2, so r = θ, is called the Fermat (or hyperbolic) spiral. Fermat’s Spiral √ While a = −1/2, or r = 1/ θ, it is called the Lituus. Lituus In 3D-XplorMath, you can change the parameter a by going to the menu Settings → Set Parameters, and change the value of aa. You can see an animation of Archimedean spirals where the exponent a varies gradually, from the menu Animate → Morph. 2 The reason that the parabolic spiral and the hyperbolic spiral are so named is that their equations in polar coordinates, rθ = 1 and r2 = θ, respectively resembles the equations for a hyperbola (xy = 1) and parabola (x2 = y) in rectangular coordinates. The hyperbolic spiral is also called reciprocal spiral because it is the inverse curve of Archimedes’ spiral, with inversion center at the origin. The inversion curve of any Archimedean spirals with respect to a circle as center is another Archimedean spiral, scaled by the square of the radius of the circle. This is easily seen as follows. If a point P in the plane has polar coordinates (r, θ), then under inversion in the circle of radius b centered at the origin, it gets mapped to the point P 0 with polar coordinates (b2/r, θ), so that points having polar coordinates (ta, θ) are mapped to points having polar coordinates (b2t−a, θ). -
Analysis of Spiral Curves in Traditional Cultures
Forum _______________________________________________________________ Forma, 22, 133–139, 2007 Analysis of Spiral Curves in Traditional Cultures Ryuji TAKAKI1 and Nobutaka UEDA2 1Kobe Design University, Nishi-ku, Kobe, Hyogo 651-2196, Japan 2Hiroshima-Gakuin, Nishi-ku, Hiroshima, Hiroshima 733-0875, Japan *E-mail address: [email protected] *E-mail address: [email protected] (Received November 3, 2006; Accepted August 10, 2007) Keywords: Spiral, Curvature, Logarithmic Spiral, Archimedean Spiral, Vortex Abstract. A method is proposed to characterize and classify shapes of plane spirals, and it is applied to some spiral patterns from historical monuments and vortices observed in an experiment. The method is based on a relation between the length variable along a curve and the radius of its local curvature. Examples treated in this paper seem to be classified into four types, i.e. those of the Archimedean spiral, the logarithmic spiral, the elliptic vortex and the hyperbolic spiral. 1. Introduction Spiral patterns are seen in many cultures in the world from ancient ages. They give us a strong impression and remind us of energy of the nature. Human beings have been familiar to natural phenomena and natural objects with spiral motions or spiral shapes, such as swirling water flows, swirling winds, winding stems of vines and winding snakes. It is easy to imagine that powerfulness of these phenomena and objects gave people a motivation to design spiral shapes in monuments, patterns of cloths and crafts after spiral shapes observed in their daily lives. Therefore, it would be reasonable to expect that spiral patterns in different cultures have the same geometrical properties, or at least are classified into a small number of common types. -
Mathematics of the Extratropical Cyclone Vortex in the Southern
ACCESS Freely available online y & W OPEN log ea to th a e im r l F C o f r e o c l Journal of a a s n t r i n u g o J ISSN: 2332-2594 Climatology & Weather Forecasting Case Report Mathematics of the Extra-Tropical Cyclone Vortex in the Southern Atlantic Ocean Gobato R1*, Heidari A2, Mitra A3 1Green Land Landscaping and Gardening, Seedling Growth Laboratory, 86130-000, Parana, Brazil; 2Aculty of Chemistry, California South University, 14731 Comet St. Irvine, CA 92604, USA; 3Department of Marine Science, University of Calcutta, 35 B.C. Road Kolkata, 700019, India ABSTRACT The characteristic shape of hurricanes, cyclones, typhoons is a spiral. There are several types of turns, and determining the characteristic equation of which spiral CB fits into is the goal of the work. In mathematics, a spiral is a curve which emanates from a point, moving farther away as it revolves around the point. An “explosive extra-tropical cyclone” is an atmospheric phenomenon that occurs when there is a very rapid drop in central atmospheric pressure. This phenomenon, with its characteristic of rapidly lowering the pressure in its interior, generates very intense winds and for this reason it is called explosive cyclone, bomb cyclone. It was determined the mathematical equation of the shape of the extratropical cyclone, being in the shape of a spiral called "Cotes' Spiral". In the case of Cyclone Bomb (CB), which formed in the south of the Atlantic Ocean, and passed through the south coast of Brazil in July 2020, causing great damages in several cities in the State of Santa Catarina. -
2 Regular Surfaces
2 Regular Surfaces In this half of the course we approach surfaces in E3 in a similar way to which we considered curves. A parameterized surface will be a function1 x : U ! E3 where U is some open subset of the plane R2. Our purpose is twofold: 1. To be able to measure quantities such as length (of curves), angle (between curves on a surface), area using the parameterization space U. This requires us to create some method of taking tangent vectors to the surface and ‘pulling-back’ to U where we will perform our calculations.2 2. We want to find ways of defining and measuring the curvature of a surface. Before starting, we recall some of the important background terms and concepts from other classes. Notation Surfaces being functions x : U ⊆ R2 ! E3, we will preserve some of the notational differences between R2 and E3. Thus: • Co-ordinate points in the parameterization space U ⊂ R2 will be written as lower case letters or, more commonly, row vectors: for example p = (u, v) 2 R2. • Points in E3 will be written using capital letters and row vectors: for example P = (3, 4, 8) 2 E3. 2 • Vectors in E3 will be written bold-face or as column-vectors: for example v = −1 . p2 Sometimes it will be convenient to abuse notation and add a vector v to a point P, the result will be a new point P + v. Open Sets in Rn The domains of our parameterized functions will always be open 2 sets in R . These are a little harder to describe than open intervals rp in R: the definitions are here for reference.