Price Dispersion, Search Externalities, and the Digital Divide

We propose a model of price competition where consumers exogenously differ in the number of prices they compare. Our model can be interpreted either as a non–sequential search model or as a network model of price competition. We show that i) if consumers who previously just sampled one firm start to compare more prices all types of consumers will expect to pay a lower price and ii) if consumers who already sampled more than one price sample (even) more prices then there exists a threshold –the digital divide– such that all consumers comparing fewer prices than this threshold will expect to pay a higher price whereas all consumers comparing more prices will expect to pay a lower price than before.

MODELLING OF DEPLOYABLE CABLE NETS FOR ACTIVE SPACE DEBRIS REMOVAL

Space debris represent a true risk for current and future activities in the circumterrestrial space, and remediation activities must be set out to guarantee the access to space in the future. For active debris removal, the development of an effective capturing mechanism remains an open issue. Among several proposals, cable nets are light, easily packable, scalable, and versatile. Nonetheless, guidance, navigation, and control aspects are especially critical in both the capture and post-capture phases. We present a finite element model of a deployable cable net. We consider a lumped mass/cable net system taking into account non-linearities arising both from large displacements and deformations, and from the different response of cables when subject to tension and compression. The problem is stated by using the nodal coordinates as Lagrangian coordinates. Lastly, the nonlinear governing equations of the system are obtained in a form ready for numerical integration

A network model of price dispersion

We analyze a model of price competition á la Bertrand in a network environment. Firms only have a limited information on the structure of network: they know the number of potential customers they can attract and the degree distribution of customers. This incomplete information framework stimulates the use of Bayesian-Nash equilibrium. We find that, if there are customers only linked to one firm, but not all of them are, then an equilibrium in randomized strategies fails to exist. Instead, we find a symmetric equilibrium in randomized strategies. Finally, we test our results on US gasoline data. We find empirical evidence consistent with firms playing random strategies

Introduction to the Open Peer-Reviewed Section on DR2 Methodology Examples

In the last twenty years Franco Moretti’s ‘distant reading’ approach has provided a fresh under­standing of literature and its historical development not by studying in detail a few particular texts (as in the so-called ‘close reading’), but rather by aggregating and analyzing large amounts of information. As members of the DR2 research group at the University of Turin—DR2: Distant Reading and Data-Driven Research in the History of Philosophy—we share the conviction that it is time to apply such methods to the history of thought. This kind of methodological innovation can be of interest for scholars working on different historical periods (ancient, medieval, modern, contem­porary) and from the perspective of different fields (history of philosophy, history of science, his­tory of ideas and intellectual history, sociology of knowledge, and so forth). A founding moment for this approach was the first DR2 Conference, held in Turin in 2017. Some of the participants to the Conference agreed to publish edited versions of the conference talks in the form of working papers, that would be subjected to an \emph{open peer review} process. We present here the results

Hybridly Aligned Liquid Crystal Films. A Monte Carlo Study of Molecular Organization and Thermodynamics

Abstract A Monte Cario simulation of a nematic Lebwohl-Lasher hybrid liquid crystal film, confined between two surfaces with antagonistic anchoring alignment, is presented. We have calculated the ordering and the molecular organization inside the film for different lateral sizes. The influence of these boundary conditions on the nematic isotropic phase transition is also investigated

Effect of modified-release methylphenidate on cognition in children with ADHD: evidence from a temporal preparation task

ADHD is associated with various cognitive deficits, including general performance decrements and specific impairments, for instance in temporal processing. However, time preparation under uncertain conditions has been under-investigated in this population. We aimed at filling this gap. We administered a variable foreperiod paradigm to children with ADHD before and after a one-month treatment with modified-release methylphenidate. Age-matched ADHD children with no treatment and healthy children were also tested as control groups with the same time-schedule. Children with ADHD had general performance deficits (longer and more variable response times), which disappeared in the experimental group after pharmacological intervention. Moreover, ADHD children showed a marked dependency on sequential foreperiod effects (i.e., slower responses for longer preceding foreperiods), especially at short current foreperiods, which were not modulated by the pharmacological treatment. In conclusion, the present findings show that methylphenidate enhances general motor processes rather than more specific time preparation processes, some of which appear deviant in ADHD

A Network Model of Price Dispersion

We analyze a model of price competition ? la Bertrand in a network environment. Firms only have a limited information on the structure of network: they know the number of potential customers they can attract and the degree distribution of customers. This incomplete information framework stimulates the use of Bayesian-Nash equilibrium. We find that, if there are customers only linked to one firm, but not all of them are, then an equilibrium in randomized strategies fails to exist. Instead, we find a symmetric equilibrium in randomized strategies. Finally, we test our results on US gasoline data. We find empirical evidence consistent with firms playing random strategies.Bertrand Competition, Bayesian- Nash Equilibrium, Mobility Index

Monte Carlo Simulations of Model Nematic Droplets

Abstract We present Monte Carlo computer simulations of model nematic droplets with radial boundary conditions and various anchoring strengths and we investigate the orientational order and the molecular organizations in these systems that mimic polymer dispersed liquid crystals (PDLC). We find a hedgehog organization at high anchoring strengths and that an ordered domain is created in the droplet center at lower strengths

A microscopic lattice model for liquid crystal elastomers

We propose a simple coarse-grained lattice model for liquid crystal elastomers and show, through large scale Monte Carlo simulations, that it can reproduce stress–strain, order, light transmission, and other experiments, including temperature effects. We focus both on homogeneously and inhomogeneously crosslinked materials