Graphs

To better illuminate the link between scaffolding and visual aids, this quasi-experimental study attempted to scaffold an intact group of 14 intermediate-level Iranian English as a foreign language (EFL) learners through providing graphs with the aim of enhancing their writing ability. Ensuring lack of familiarity with eight unknown words, they were scaffolded through visual images. The scaffolding process included three respective phases of contingency, fading, and transferring. As post-tests for checking the learners' understanding of and opinion about the graph scaffolding process, a researcher-made questionnaire and a semi-structured interview followed the treatment phase. The results of the questionnaire showed that visual scaffolding aided the learners to better grasp the meaning of the target vocabularies and even some grammatical points in the materials. Moreover, the visual scaffolding helped them to produce the material in different modalities. The results also indicat...

Researchers from the University of Melbourne's New Technologies for Teaching Mathematics project created a lesson for the Year 10 students at their Victorian research schools. Two important goals of secondary school mathematics education are to build students' conceptual knowledge and to teach students to think mathematically. Mathematics education research supports the notion that seeing concepts represented in multiple ways both supports students' sense-making and enriches their learning. The design of lessons must be carefully considered in order not to create excessive cognitive load for the learner. The study focused on one 'lesson', designed to provide exemplars for lessons where new powerful, mathematically able integrated documents (Nspire) are used to support students' exploration of various representations of a given mathematical problem. Based on applications of quadratic functions, 'Marina's Fish Shop' was designed as a capstone lesson...

An algorithm based on a recurrent neural Wang’s network and the WTA (“Winner takes all”) principle is applied to the construction of Hamiltonian cycles in graphs of distributed computer systems (CSs). The algorithm is used for: 1) regular graphs (2D- and 3D-tori, and hypercubes) of distributed CSs and 2) 2D-tori disturbed by removing an arbitrary edge. The neural network parameters for the construction of Hamiltonian cycles and suboptimal cycles with a length close to that of Hamiltonian ones are determined. Our experiments show that the iterative method (Jacobi, Gauss-Seidel, or SOR) used for solving the system of differential equations describing a neural network strongly affects the process of cycle construction and depends on the number of torus nodes.

ABSTRACT The Doppler shift is a frequency change of a repetitive effect, as measured by a receiver, due to the motion of the wave emitter, to the motion of the wave receiver, or both. A demonstration of the effect is provided by the sound of a car's horn that changes from a higher pitch to a lower pitch when a car drives past.1 Most derivations of the Doppler formula assume sinusoidal waves.2-4 We want to call the attention of readers to a derivation that uses a graphical representation based on a graph of position versus time.5 We will adopt a particle model of machine gun bullets fired at a constant period,6-8 thus getting a derivation that just requires the knowledge of kinematics. Furthermore, we will explain how to introduce the time dilation in order to get the formula for the relativistic Doppler shift.

In this paper, we deal with the notion of star coloring of graphs. A star coloring of an undirected graph G is a proper vertex coloring of G (i.e., no two neighbors are assigned the same color) such that any path of length 3 in G is not bicolored. We give the exact value of the star chromatic number of different families of graphs such as trees, cycles, complete bipartite graphs, outerplanar graphs and 2-dimensional grids. We also study and give bounds for the star chromatic number of other families of graphs, such as hypercubes, tori, d-dimensional grids, graphs with bounded treewidth and planar graphs.

“O libro parti per Roma e se ti chiederanno da dove vieni, risponderai che vieni dalla regione della Via Emilia” (Marziale: Epigrammi, III, 4)

Già in epoca romana la via Emilia era considerata il fulcro di un’area territoriale. Asse di congiungimento tra il Mediterraneo dominato da Venezia e l’Europa continentale, la via Emilia viene definita una mesopoli (Farinelli 2019) cioè una regione con città di medie e piccole dimensioni (14, più due decentrate), a poca distanza tra loro, di forte identità storica e culturale, che nella prima età moderna hanno fatto parte di tre stati diversi: le legazioni pontificie, il ducato Estense e il ducato Farnese. Questa la prospettiva geografica e culturale da cui prende le mosse l’idea del convegno. A fronte di numerosi studi sull’importanza della Via Emilia come arteria socio-economica, meno si sono approfonditi i rapporti intellettuali tra le città emiliane nella prima età moderna. Il convegno intende contribuire a colmare tale lacuna concentrandosi sulle accademie fiorite nella regione della Via Emilia.
Dopo le grandi censure sette e ottocentesche sul fenomeno culturale delle accademie, gli studi si sono spesso concentrati su accademie famose (Intronati, Lincei, Accademia della Fama, Incogniti di Venezia, Oziosi di Napoli, ecc.), su individui famosi che di accademie hanno fatto parte (Marino, Galilei, Tasso, ecc.), su pubblicazioni particolarmente significative scaturite da ambienti accademici, oppure su città sedi di accademie importanti (Siena, Venezia, Firenze, Roma, ecc.).
Il recente sviluppo a livello internazionale degli studi sulle accademie italiane ha seguito due direzioni, spesso intrecciate, che insieme danno conto della vastità del fenomeno accademico e delle sue implicazioni. Sulla scia dell’opera di Michele Maylender, poi approfindita da Amedeo Quondam, vi è l’evoluzione in formato digitale del censimento delle accademie, dei loro membri e delle loro pubblicazioni (si vedano le banche dati relazionali Italian Academies 1525–1700, realizzata presso la British Library, e Accademie siciliane nel regno asburgico 1400–1701, di Delphine Montoliu – Università di Tolosa). Inoltre, vi è l’aggiornamento della ricerca su accademie, e relazioni tra accademie, meno frequentate dagli studiosi (Gurreri et al. 2015, Testa 2015, Everson et al. 2016, Chiummo et al. 2017, Alfonzetti et al. 2017, Sampson 2019). Le realtà periferiche, insieme all’attenzione per le relazioni tra accademie nella fervente attività culturale della prima età moderna, sono adesso al centro dell’attenzione degli studiosi (Battistini 2008).
Diversamente dalle regioni sottomesse a un dominio centrale (Toscana, domini veneziani, Regno di Napoli), le città sulla via Emilia e quelle immediatamente adiacenti (Ferrara e Ravenna), non godono di una coerenza storico-istituzionale altrettanto unitaria, ma godono di una notevole coesione se analizzate in una prospettiva geografica che ha come suo fulcro proprio la Via Emilia, l’asse viario che da secoli connette praticamente tutte le città della regione adesso conosciuta come Emilia Romagna. Per questo motivo è necessario analizzare nel loro insieme le realtà accademiche di questa speciale area, e rendersi conto delle loro diversità, affinità, scambi e produzioni siano esse pubblicazioni a stampa o manoscritte, spettacoli teatrali, eventi musicali o produzioni artistiche. Scopo primario del convegno è dunque una serie di interventi che mettano in luce le realtà accademiche sorte lungo la via Emilia e i suoi dintorni, i loro intrecci e sviluppi, e la presenza delle accademie ebraiche in alcune città dove la presenza di questa minoranza religiosa era sentita. Altri due aspetti che si intende integrare, riguardano 1) lo sviluppo di strumenti di informatica umanistica (grafo) per lo studio delle accademie e dei loro intrecci, in collaborazione con l’Università di Pisa; 2) la dimostrazione della permanenza del termine accademia e della sua flessibilità, attraverso la presentazione di un progetto di ricerca sulla Parker Academy a Clermontville (Ohio) a metà Ottocento.

The content is intended to enable audience with better understanding on analytics, steps prior to visualization, tools available as well as deep dive on Tableau. The dataset along with how-to-create charts and dashboard should help in quick hands-on with Tableau

The study of cycles, particularly Hamiltonian cycles, is very important in many applications. Bondy posited his famous metaconjecture, that every condition sufficient for Hamiltonicity actually guarantees a graph is pancyclic. Pancyclicity is a stronger structural property than Hamiltonicity. An even stronger structural property is for a graph to be cycle extendable. Hendry conjectured that any graph which is Hamiltonian and chordal is cycle extendable. In this dissertation, cycle extendability is investigated and generalized. It is proved that chordal 2-connected K1,3-free graphs are cycle extendable. S-cycle extendability was defined by Beasley and Brown, where S is any set of positive integers. A conjecture is presented that Hamiltonian chordal graphs are {1, 2}-cycle extendable. Dirac’s Theorem is an classic result establishing a minimum degree condition for a graph to be Hamiltonian. Ore’s condition is another early result giving a sufficient condition for Hamiltonicity. In thi...

Over the past several years, researchers within the ONR-sponsored Adaptive Architectures for Command and Control (A2C2) research program have been investigating the concept of organizational "congruence." These model-based theories loosely state that the better an organization is matched structurally to the overall mission (as measured using a multi-variant set of workload/congruence metrics) the better will that organization perform, and that mismatches are potential drivers for the adaptation of organization structure. To test the congruence theories and their corollaries in a laboratory experiment, the authors' approach was to seek two sufficiently disparate organizational structures and then design two missions (or scenarios) that would exploit the differences in these two structures. One scenario would be "tuned" to organization 1 to exhibit a high degree of congruence, but at the same time it would be "mismatched" (i.e., exhibit low congruence...

This report presents a methodology for analyzing vertiport capacity and delays. Based on available information, deterministic models were developed to estimate vertiport capacity, analytic queuing models were developed to estimate the delays at vertiports during steady demand periods, and simulation models were developed to estimate delays during peak periods when traffic exceeds capacity. A practical capacity, defined as that traffic volume at which average delays are four minutes per operation, can be determined from a volume versus delay curve. Results show that vertiport capacity is more likely to be limited by airspace separations or gate availability than by touchdown and liftoff area (TLOF) occupancy times. Equations are provided for estimating relations among aircraft arrival rates, required number of gates, and gate occupancy times. These may be used to determine the required number of TLOF's or gates in particular situations.