Search results for "network structure"
showing 10 items of 25 documents
The Potential Role of Direct and Indirect Contacts on Infection Spread in Dairy Farm Networks.
2017
Animals’ exchanges are considered the most effective route of between-farm infectious disease transmission. However, despite being often overlooked, the infection spread due to contaminated equipment, vehicles, or personnel proved to be important for several livestock epidemics. This study investigated the role of indirect contacts in a potential infection spread in the dairy farm network of the Province of Parma (Northern Italy). We built between-farm contact networks using data on cattle exchange (direct contacts), and on-farm visits by veterinarians (indirect contacts). We compared the features of the contact structures by using measures on static and temporal networks. We assessed the d…
Metabolic Pathway Analysis 2019: Systems (biology+medicine) : 12th-16th August 2019, Riga, Latvia
2019
Network structure and optimal technological innovation
2019
The role of networks in the emergence, diffusion and evolution of technological innovations has attracted much theoretical and empirical attention. Yet, much of the work has explored the role of undirected and homogeneous networks. In real cases, many networks are directed. The flow of information, benefits or observations is directed from one node towards another node. Real networks are also heterogeneous, for example, few nodes have a high degree while many others have a low degree. In this article, we report on the results of an evolutionary agent-based model in which a group of agents, in our case firms, collectively search a complex (rugged) technological landscape and observe each oth…
Thermally Induced Structural Modification of Silica Nanoparticles Investigated by Raman and Infrared Absorption Spectroscopies
2010
We report an experimental investigation by Raman and infrared (IR) absorption spectroscopies on the structural modifications induced by isochronal thermal treatments on amorphous SiO2 nanoparticles (fumed silica). In particular, three different commercial types of this material, characterized by particle mean diameters of 7, 14, and 40 nm, were subjected to thermal treatments from 100 up to 1000 °C. We found that some properties of fumed silica, such as the SiOSi mean bond angle, ring size distribution, and surface adsorbed water content, are drastically different from those of common bulk silica materials and intimately related to the particles' dimension. The SiOSi mean bond angle, probed…
(Pr4N)4[Ag3Fe2(ECN)12]--anionic network structures with mutual interpenetration.
2006
How to derive the analytical capacity model for not-conventional urban roundabouts
2008
The inapplicability of current methods for analyzing operations of urban not-conventional roundabouts (i.e. not referable to standard schemes) hampers seriously the assessment of their operational performances. Moreover, local constraints and the road network structure have produced lots of geometric layouts that make hard to propose an only framework to explain performances of not-conventional roundabouts. Also for these intersections it is hoped to have scientifically based methods to analyze operations with a proper reliability. Starting from these considerations, the paper shows the conceptual path followed to analyze operations at not-conventional roundabouts along an arterial of Paler…
PageRank model of opinion formation on Ulam networks
2013
We consider a PageRank model of opinion formation on Ulam networks, generated by the intermittency map and the typical Chirikov map. The Ulam networks generated by these maps have certain similarities with such scale-free networks as the World Wide Web (WWW), showing an algebraic decay of the PageRank probability. We find that the opinion formation process on Ulam networks have certain similarities but also distinct features comparing to the WWW. We attribute these distinctions to internal differences in network structure of the Ulam and WWW networks. We also analyze the process of opinion formation in the frame of generalized Sznajd model which protects opinion of small communities.
Gene Duplication Models and Reconstruction of Gene Regulatory Network Evolution from Network Structure
2016
The work was supported by Latvian Council of Science grant 258/2012 and Latvian State Research programme project NexIT (2014-2017).
Superintendent Leadership in Hierarchy and Network
2015
School superintendents are coupled hierarchically with the top apex of municipality organization through their membership of leadership teams and through personal ties to the top municipal manager, which provides opportunities to take part in strategic decision-making processes beyond the educational sector. Superintendents are also vertically linked to their school leaders through strong and dense network ties. Along the horizontal axis superintendents are active network players with peers, for example through superintendent associations or more frequently mentioned through personal ties to superintendent colleagues. Superintendents are linked to school boards through strong formal ties. I…
The Dynamic of Innovation Networks: A Switching Model on Technological Change
2012
In this paper we introduce an agent-based model with heterogeneous firms which compare their mutual innovation strategies on different network structures. By implementing a dynamic behavioral switching via a fitness mechanism based on agents performance, companies can endogenously modify their tactics of technological change and switch among three groups: stand-alone innovators, collaborative innovators and imitators. We focus the analysis on the impact of these three innovation categories on micro, meso and macro aggregates. Our findings show that collaborative companies are those having the highest positive impact on the economic system. Moreover, we study the properties of the emerging n…