Search results for "Steiner"
showing 10 items of 47 documents
Efficient Tree Construction for the Multicast Problem
1999
Additive Steiner triple systems
2014
A Steiner triple system is additive if it can be embedded in a commutative group in such a way that the sum of the three points in any given block is zero. In this paper we show that a Steiner triple system is additive if and only if it is the point-line design of either a projective space PG(d,2) over GF(2) or an affine space AG(d,3) over GF(3), for d ≥ 1. Our proof is based on algebraic arguments and on the combinatorial characterization of finite projective geometries in terms of Veblen points.
An algebraic representation of Steiner triple systems of order 13
2021
Abstract In this paper we construct an incidence structure isomorphic to a Steiner triple system of order 13 by defining a set B of twentysix vectors in the 13-dimensional vector space V = GF ( 5 ) 13 , with the property that there exist precisely thirteen 6-subsets of B whose elements sum up to zero in V , which can also be characterized as the intersections of B with thirteen linear hyperplanes of V .
Steiner Loops of Affine Type
2020
Steiner loops of affine type are associated to arbitrary Steiner triple systems. They behave to elementary abelian 3-groups as arbitrary Steiner Triple Systems behave to affine geometries over GF(3). We investigate algebraic and geometric properties of these loops often in connection to configurations. Steiner loops of affine type, as extensions of normal subloops by factor loops, are studied. We prove that the multiplication group of every Steiner loop of affine type with n elements is contained in the alternating group An and we give conditions for those loops having An as their multiplication groups (and hence for the loops being simple).
Optimal Resource Discovery Paths of Gnutella2
2008
This paper shows that the performance of peer-to-peer resource discovery algorithms is upper bounded by a k-Steiner minimum tree and proposes an algorithm locating near-optimal query paths for the peer-to-peer resource discovery problem. Global knowledge of the topology and the resources from the peer-to-peer network are required as an input to the algorithm. The algorithm provides an objective measure for defining how good local search algorithms are. The performance is evaluated in simulated peer-to-peer scenarios and in the measured Gnutella2 P2P network topology with four local search algorithms: breadth-first search, self-avoiding random walker, highest degree search and Dynamic Query …
On Holditch's theorem and related kinematics
2019
El teorema de Holditch es un resultado clásico sobre áreas de curvas planas generadas por el movimiento de segmentos. Esta construcción está estrechamente relacionada con otros tipos de curvas como, por ejemplo, curvas paralelas, curvas de anchura constante o curvas de bicicletas. Se compilan las propiedades básicas de este tipo de curvas y se da una revisión histórica sobre el teorema de Holditch y teoremas relacionados de cinemática. Primero, la situación plana de Holditch se define rigurosamente y se consideran ciertos problemas como la existencia de dicha construcción o el modo de evitar movimientos retrógrados en el segmento que se va moviendo. En el enunciado del teorema de Holditch a…
Pattern Dystrophy of the Macula in a Case of Steinert Disease
2013
<b><i>Introduction:</i></b> Myotonic dystrophies are typically associated with ocular complications like ptosis, weakness of the ocular muscle and cataracts, but also with less recognized retinal changes. <b><i>Case Report:</i></b> A 41-year-old female with type 1 myotonic dystrophy complained of progressive vision loss. Slit lamp examination revealed the presence of typical bilateral polychromatic cataract with posterior subcapsular component. Dilated fundus examination was remarkable for bilateral macular depigmented changes. Multimodal imaging analysis of the macula suggested the presence of a butterfly-shaped pattern dystrophy. <b>&l…
Clinical Utility of a Unique Genome-Wide DNA Methylation Signature for KMT2A-Related Syndrome
2022
Wiedemann–Steiner syndrome (WDSTS) is a Mendelian syndromic intellectual disability (ID) condition associated with hypertrichosis cubiti, short stature, and characteristic facies caused by pathogenic variants in the KMT2A gene. Clinical features can be inconclusive in mild and unusual WDSTS presentations with variable ID (mild to severe), facies (typical or not) and other associated malformations (bone, cerebral, renal, cardiac and ophthalmological anomalies). Interpretation and classification of rare KMT2A variants can be challenging. A genome-wide DNA methylation episignature for KMT2A-related syndrome could allow functional classification of variants and provide insights into the pathoph…
Kunnon kansalaisen kasvatus : kansalaiskasvatuksen käsite, tavoitteet ja menetelmät Friedrich Wilhelm Foersterin (1869-1966) ja Georg Kerschensteiner…
2004
"Steinerpedagoginen malli ja metodi on siinä mielessä niinku. ihana. että kaikki oppii sillo alaluokilla. ja tulee kaikki on mukana /siinä/," : stein…
2012
Ylikotila, T. 2012. Steinerkieltenopettajien käsityksiä opettajuudesta. Jyväskylän yliopisto. Opettajankoulutuslaitos. Kielten laitos. Pro gradu -tutkielma, 153 s. Tutkimukseni tarkoitus on selvittää, millaisia käsityksiä steinerkoulun kieltenopettajilla on omasta sekä steinerkoulun opettajuudesta ja erityisesti kieltenopettajuudesta. Tutkimuksen kohteena ovat saksanopettajat, mutta mukana on myös yksi ruotsin- ja luokanopettaja, joka tarjoaa tutkimuksen kannalta olennaista tietoa. Lisäksi pohdin, millaisia elementtejä opettajat liittävät oppitunnin rakenteeseen, millaisia käsityksiä heillä on yksittäisen oppilaan asemasta tunnilla sekä millaista arviointia heillä tapahtuu. Tutkimukseeni os…