5,881 research outputs found
Systemic risk assessment through high order clustering coefficient
© 2020, Springer Science+Business Media, LLC, part of Springer Nature. In this article we propose a novel measure of systemic risk in the context of financial networks. To this aim, we provide a definition of systemic risk which is based on the structure, developed at different levels, of clustered neighbours around the nodes of the network. The proposed measure incorporates the generalized concept of clustering coefficient of order l of a node i introduced in Cerqueti et al. (2018). Its properties are also explored in terms of systemic risk assessment. Empirical experiments on the time-varying global banking network show the effectiveness of the presented systemic risk measure and provide insights on how systemic risk has changed over the last years, also in the light of the recent financial crisis and the subsequent more stringent regulation for globally systemically important banks.
This is a post-peer-review, pre-copyedit version of an article published in Annals of Operations Research. The final authenticated version is available online at: http://dx.doi.org/10.1007/s10479-020-03525-8
Influence measures in subnetworks using vertex centrality
This work deals with the issue of assessing the influence of a node in the entire network and in the subnetwork to which it belongs as well, adapting the classical idea of vertex centrality. We provide a general definition of relative vertex centrality measure with respect to the classical one, referred to the whole network. Specifically, we give a decomposition of the relative centrality measure by including also the relative influence of the single node with respect to a given subgraph containing it. The proposed measure of relative centrality is tested in the empirical networks generated by collecting assets of the S&P 100, focusing on two specific centrality indices: betweenness and eigenvector centrality. The analysis is performed in a time perspective, capturing the assets influence, with respect to the characteristics of the analysed measures, in both the entire network and the specific sectors to which the assets belong.
This is a post-peer-review, pre-copyedit version of an article published in Soft Computing. The final authenticated version is available online at: http://dx.doi.org/10.1007/s00500-019-04428-y
Responses of Coccidia-Vaccinated Broilers to Essential Oil Blends Supplementation up to Forty-Nine Days of Age
Coccidiosis control may become a greater problem as the use of growth-promoting antibiotics (GPA) and ionophores declines. Vaccination with live oocysts may turn into a popular alternative to the use of coccidiostats in broilers, although cocci vaccination is frequently linked to temporary lower performance in young flocks. This experiment evaluates the dietary supplementation of 2 specific essential oil (EO) blends (Crina Poultry and Crina Alternate), either as alternatives to GPA and ionophores (BMD + Coban) or as feed additives that help to improve the performance of cocci-vaccinated broilers. Live performance and lesion scores were observed. These 2 specific EO blends differ in their efficacy to promote growth. Chickens that were not cocci vaccinated and were fed Crina Poultry had better feed conversion ratio (FCR) than the unmedicated control treatment in the starter period. The same EO improved FCR in cocci-vaccinated birds in the finisher period in comparison to the negative control group, but those responses were not significantly different from other treatments or significant at 49 d of age. No significant differences were observed in lesion scores at 37 d. Diets supplemented with a GPA-ionophore combination consistently supported the best BW gain and FCR in each period and the entire grow-out period. No significant beneficial or deleterious effects on live performance were observed due to these specific EO blends in cocci-vaccinated broilers
Sobre la dependencia del hábito cristalino respecto de la hidrodinámica del medio en que crece el cristal, referido al caso del NaCl
Se describe un modelo explicativo de la modificación de hábito de los cristales de NaCl, por acción de la hidrodinámica de la solución madre, basado en los diferentes mecanismos de aporte sobre caras homólogas
Sobre la dependencia del hábito cristalino respecto de la hidrodinámica del medio en que crece el cristal, referido al caso del NaCl
Se describe un modelo explicativo de la modificación de hábito de los cristales de NaCl, por acción de la hidrodinámica de la solución madre, basado en los diferentes mecanismos de aporte sobre caras homólogas
An optimization model for minimizing systemic risk
This paper proposes an optimal allocation model with the main aim to minimize systemic risk related to the sovereign risk of a set of countries. The reference methodological environment is that of complex networks theory. Specifically, we consider the weighted clustering coefficient as a proxy of systemic risk, while the interconnections among countries are captured by the relationships among default probabilities of the set of countries under consideration. The selected optimization criterion is based on minimization of the mean absolute deviation. We perform empirical analyses to validate the theoretical predictions, and interpret the findings in the context of the proposed model
Feasible database querying using a visual end-user approach
This is the author's version of the work. It is posted here for your personal use. Not for redistribution. The definitive Version of Record was published in Proceedings of the 2nd ACM SIGCHI symposium on Engineering interactive computing systems, http://dx.doi.org/10.1145/1822018.1822047Querying databases is a common daily task carried out by a great deal of end-users who do not have specific skills in SQL language. Today, most of the database interaction is achieved by means of query interfaces provided by the database environment. However, most of these interfaces suffer from expressive limitations, since they are mostly based on metaphors that drastically restrict the expressiveness of the SQL language that is generated and executed in the background. In this paper, we present a visual interaction language and tool focused on easily querying databases by end-users. We make no assumption on the level of the user's experience with query languages, as our visual metaphor is intended for querying databases by unskilled end-users and also leveraging the restriction on the expressiveness of the queries created by them. We also report on some late braking results obtained by an experiment carried out with real users.The work reported in this paper is being partially supported by the founded projects TIN2008-02081/TIN and S2009/TIC-1650
Social Opportunities and Digitalized Communication of Genshin Impact Players
Genshin Impact (GI) became a global trend for online gaming culture in 2020. Many players greatly value it because of what it offers to their community. This study was conducted to understand the social interactions and communicative practices of Ilokano players of Genshin Impact. Guided by the concepts of the ethnomethodology tradition of qualitative communication research, 6 GI players participated in in-depth interviews and virtual immersion to document their narratives and practices on their social interactions and communicative practices. The theorizing evinced that social opportunities are the achievement in playing GI that is comprised of six sub-themes, which include: (1) Virtual Amity; (2) Virtual Emotional Sharing; (3) Introvert Friendly; (4) Cross-Cultural Virtual Encounters; (5) Otaku Community; and (6) Third-place. Meanwhile, digitalized communication emerged as the core category describing the communicative practices of GI players that consists of four sub-themes which include: (1) Discord (Extension of CMC); (2) Meta (Extension of CMC); (3) Genshin Impact Emojis; and (4) Face-to-Face. Hence, this theorizing revealed that playing Genshin Impact provides social opportunities and digitalized communication, improving GI players\u27 social lives
Facilitating the interaction with data warehouse schemas through a visual web-based approach
In most respects, there are implicit drawbacks concerning representation and interaction with data in relational-database applications. On the one hand, there is a lack of expressiveness and ease of use in the user interfaces that handle such data. On the other hand, there is an implicit need for interactive end-user visual tools to query data and avoid dependency on programming languages. The main aim of this work is to study the problem of database interaction and usability, comparing existing solutions and providing a new approach that overcomes existing problems. We propose a web-based tool that manipulates Data Warehouse schemas by using a visual language to represent the database structure and providing several visualization techniques that facilitate the interaction and creation of queries involving different levels of complexity. We based our research on an End-User Development approach that has been evaluated to obtain some initial usability indicators
Foot pressure distributions during walking in African elephants (Loxodonta africana)
Elephants, the largest living land mammals, have evolved a specialized foot morphology to help reduce locomotor pressures while supporting their large body mass. Peak pressures that could cause tissue damage are mitigated passively by the anatomy of elephants' feet, yet this mechanism does not seem to work well for some captive animals. This study tests how foot pressures vary among African and Asian elephants from habitats where natural substrates predominate but where foot care protocols differ. Variations in pressure patterns might be related to differences in husbandry, including but not limited to trimming and the substrates that elephants typically stand and move on. Both species' samples exhibited the highest concentration of peak pressures on the lateral digits of their feet (which tend to develop more disease in elephants) and lower pressures around the heel. The trajectories of the foot's centre of pressure were also similar, confirming that when walking at similar speeds, both species load their feet laterally at impact and then shift their weight medially throughout the step until toe-off. Overall, we found evidence of variations in foot pressure patterns that might be attributable to husbandry and other causes, deserving further examination using broader, more comparable samples
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