How social comparison influences reference price formation in a service context

What is the influence on reference price when the source of price information is anonymous versus social? This article investigates the formation of reference prices given an observed sequence of past prices in a service context. An experimental study suggests that, considering the same price information, if the source is social (i.e., the prices paid by colleagues), then consumers want to pay less. More specifically, social comparison changes the way individuals weigh information, attributing more importance to the lowest historical prices and to the range in price variations

Study of impact on helicopter blade

This article presents a study of damage in structures that are similar to helicopter blade sections, subjected to an impact. These complex composite structures were impacted by a steel ball of 125 g at impact speed ranging from 30 to 130 m/s. This led to properly highlight the kinematics of the impact and to define the sequence of the damage’s mechanisms. An explicit FE model is also presented. The damage modelling of the roving is performed through a scale change. It allows a good representation of observed experimental behaviour. As the mesh density is low, it can be used for the modelling of a real structure

Periodic representations and rational approximations of square roots

In this paper the properties of R\'edei rational functions are used to derive rational approximations for square roots and both Newton and Pad\'e approximations are given as particular cases. As a consequence, such approximations can be derived directly by power matrices. Moreover, R\'edei rational functions are introduced as convergents of particular periodic continued fractions and are applied for approximating square roots in the field of p-adic numbers and to study periodic representations. Using the results over the real numbers, we show how to construct periodic continued fractions and approximations of square roots which are simultaneously valid in the real and in the p-adic field

Costs and Technology of Public Transit Systems in Italy:Some Insights to Face Inefficiency

This study provides fresh evidence about the characteristics of technology and cost structure of public transit systems in Italy. The aim is to suggest useful guidelines for facing detected inefficiencies. The analysis is carried out through the estimation of a translog variable cost function. The sample includes 45 Italian public companies. Firms are observed in the years 1996, 1997 and 1998, and operate both in the urban and extra-urban compartments. Results support previous evidence on the existence of natural monopoly at local level and stress the importance of the average speed of vehicles in explaining cost differences between companies. We conclude that cost benefits can be achieved by promoting mergers between firms (whenever possible), introducing some forms of "competition-for-the-market" (e.g., competitive tendering for the single license) and taking more care of the local traffic regulation.

Polynomial sequences on quadratic curves

In this paper we generalize the study of Matiyasevich on integer points over conics, introducing the more general concept of radical points. With this generalization we are able to solve in positive integers some Diophantine equations, relating these solutions by means of particular linear recurrence sequences. We point out interesting relationships between these sequences and known sequences in OEIS. We finally show connections between these sequences and Chebyshev and Morgan-Voyce polynomials, finding new identities

Groups and monoids of Pythagorean triples connected to conics

We define operations that give the set of all Pythagorean triples a structure of commutative monoid. In particular, we define these operations by using injections between integer triples and $3 \times 3$ matrices. Firstly, we completely characterize these injections that yield commutative monoids of integer triples. Secondly, we determine commutative monoids of Pythagorean triples characterizing some Pythagorean triple preserving matrices. Moreover, this study offers unexpectedly an original connection with groups over conics. Using this connection, we determine groups composed by Pythagorean triples with the studied operations

Linear divisibility sequences and Salem numbers

We study linear divisibility sequences of order 4, providing a characterization by means of their characteristic polynomials and finding their factorization as a product of linear divisibility sequences of order 2. Moreover, we show a new interesting connection between linear divisibility sequences and Salem numbers. Specifically, we generate linear divisibility sequences of order 4 by means of Salem numbers modulo 1