scholarly journals Structural and spectral properties of generative models for synthetic multilayer air transportation networks

PLoS ONE ◽  
2021 ◽  
Vol 16 (10) ◽  
pp. e0258666
Author(s):  
Marzena Fügenschuh ◽  
Ralucca Gera ◽  
José Antonio Méndez-Bermúdez ◽  
Andrea Tagarelli
Keyword(s):  
Matrix Theory ◽  
Transportation Networks ◽  
Spectral Characteristics ◽  
Air Transportation ◽  
The United States ◽  
Generative Models ◽  
Layer By Layer ◽  
Systematic Analysis ◽  
Targeted Attacks ◽  
Point To Point

To understand airline transportation networks (ATN) systems we can effectively represent them as multilayer networks, where layers capture different airline companies, the nodes correspond to the airports and the edges to the routes between the airports. We focus our study on the importance of leveraging synthetic generative multilayer models to support the analysis of meaningful patterns in these routes, capturing an ATN’s evolution with an emphasis on measuring its resilience to random or targeted attacks and considering deliberate locations of airports. By resorting to the European ATN and the United States ATN as exemplary references, in this work, we provide a systematic analysis of major existing synthetic generation models for ATNs, specifically ANGEL, STARGEN and BINBALL. Besides a thorough study of the topological aspects of the ATNs created by the three models, our major contribution lays on an unprecedented investigation of their spectral characteristics based on Random Matrix Theory and on their resilience analysis based on both site and bond percolation approaches. Results have shown that ANGEL outperforms STARGEN and BINBALL to better capture the complexity of real-world ATNs by featuring the unique properties of building a multiplex ATN layer by layer and of replicating layers with point-to-point structures alongside hub-spoke formations.

scholarly journals Correction: Structural and spectral properties of generative models for synthetic multilayer air transportation networks

PLoS ONE ◽  
2021 ◽  
Vol 16 (12) ◽  
pp. e0262383
Author(s):  
Marzena Fügenschuh ◽  
Ralucca Gera ◽  
José Antonio Méndez-Bermúdez ◽  
Andrea Tagarelli
Keyword(s):  
Spectral Properties ◽  
Transportation Networks ◽  
Air Transportation ◽  
Generative Models

Dynamics of Disruption and Recovery in Air Transportation Networks

2021 ◽  
Author(s):  
Max Li ◽  
Karthik Gopalakrishnan ◽  
Hamsa Balakrishnan ◽  
Sang Hyun Shin ◽  
Darsh Jalan ◽  
...  
Keyword(s):  
Transportation Networks ◽  
Air Transportation

Are You Experienced? US Ambassadors and International Crises, 1946–2014

2021 ◽  
Vol 17 (4) ◽  
Author(s):  
Paul K MacDonald
Keyword(s):  
United States ◽  
International Politics ◽  
The United States ◽  
International Crises ◽  
Systematic Analysis ◽  
Militarized Disputes ◽  
Political Appointees ◽  
Significant Difference ◽  
The Military ◽  
Sizable Number

Abstract How important are ambassadors in international politics? While a growing body of research stresses the importance of diplomacy in international politics, it remains unclear if individual ambassadors make a significant difference or what attributes make for an effective ambassador. This paper explores these questions through a systematic analysis of 2,730 US ambassadors between 1946 and 2014. The United States is distinctive in that it sends a sizable number of noncareer political appointees to serve as ambassadors. This provides a unique opportunity to examine how an ambassador's experience shapes where they are placed and how they perform. Using various techniques to address selection effects, including matching, I find that the United States is less likely to experience a militarized dispute with a host nation when it is represented by a political ambassador. Moreover, political ambassadors with professional experience in politics or the military, those who are close to the president, and those who are appointed in permissive congressional environments are less likely to experience militarized disputes during their tenure. Individual ambassadors matter, but diplomatic experience alone is not the only attribute that makes for an effective ambassador.

Network dynamics on the Chinese air transportation multilayer network

2021 ◽  
pp. 2150070
Author(s):  
Yong Yang ◽  
Kai-Jun Xu ◽  
Chen Hong
Keyword(s):  
Success Rate ◽  
Transportation Networks ◽  
Human Mobility ◽  
Transportation Network ◽  
Air Transportation ◽  
Transfer Number ◽  
Multilayer Network ◽  
Scheduling Model ◽  
Network Mechanism ◽  
Random Failures

Air transportation networks play important roles in human mobility. In this paper, from the perspective of multilayer network mechanism, the dynamics of the Chinese air transportation network are extensively investigated. A multilayer-based passengers re-scheduling model is introduced, and a multilayer cooperation (MC) approach is proposed to improve the efficiency of network traffic under random failures. We use two metrics: the success rate and the extra transfer number, to evaluate the efficiency of re-scheduling. It is found that a higher success rate of passengers re-scheduling can be obtained by MC, and MC is stronger for resisting the instability of the capacity of links. Furthermore, the explosion of the number of extra transfer can be well restrained by MC. Our work will highlight a better understanding of the dynamics and robustness of the Chinese air transportation network.

scholarly journals Heavy Metals Characterization of Sludge from a Philippine Recycling Paper Mill

2004 ◽  
Vol 4 (2) ◽  
pp. 58
Author(s):  
Lorraine A. Carrillo ◽  
Susan M. Gallardo
Keyword(s):  
Heavy Metals ◽  
Metal Content ◽  
Paper Industry ◽  
Paper Mill ◽  
The United States ◽  
White Paper ◽  
International Standards ◽  
Organic Fertilizers ◽  
Point To Point ◽  
Maximum Allowable Content

Wastewater treatment sludge, which is the largest volume residual waste stream generated by the pulp and paper industry, is generally disposed of in a dedicated landfill. Composting the sludge is an alternative method proposed by the Asian Regional Research Program on Environmental Technology-De La Salle University (ARRPET-DLSU) Minor Issue Group. The Philippine Department of Agriculture's (DA) standards for an organic fertilizer's maximum allowable content of heavy metals provided the legislative regulation for the conversion of sludge to compost. The research was designed to characterize the sludge samples from TIPCO, a Philippine paper-recycling mill, and establish whether the sludge contained the heavy metals cadmium, chromium, lead, mercury, nickel, and zinc using atomic absorption spectrophotometer (MS). Sampling was done for four weeks during newsprint and white paper production. Three discharge terminals were established as sampling points. The samples showed that the metal content of the sludge vary from point to point and was highest throughout the manufacture of white paper. Chromium, mercury, and nickel, however, were nondetectable in all the samples, while cadmium was detectable only in very few samples. Lead and zinc were present at all three points and were highest at the de inking sludge. Comparing the results with Part 503 of the United States EPA and the DA's guidelines for organic fertilizers yield significantly lower parameter values. Composting the sludge was, therefore, found to be a feasible option for recycling paper-mill sludge since the metal content were very low compared to local and international standards.

scholarly journals The Banff Working Group Classification of Definitive Polyomavirus Nephropathy: Morphologic Definitions and Clinical Correlations

2017 ◽  
Vol 29 (2) ◽  
pp. 680-693 ◽  
Author(s):  
Volker Nickeleit ◽  
Harsharan K. Singh ◽  
Parmjeet Randhawa ◽  
Cinthia B. Drachenberg ◽  
Ramneesh Bhatnagar ◽  
...  
Keyword(s):  
Repeated Measures ◽  
Working Group ◽  
Classification Scheme ◽  
Clinical Presentation ◽  
Interstitial Fibrosis ◽  
The United States ◽  
Systematic Analysis ◽  
Definition Of ◽  
Morphologic Classification

Polyomavirus nephropathy (PVN) is a common viral infection of renal allografts, with biopsy-proven incidence of approximately 5%. A generally accepted morphologic classification of definitive PVN that groups histologic changes, reflects clinical presentation, and facilitates comparative outcome analyses is lacking. Here, we report a morphologic classification scheme for definitive PVN from the Banff Working Group on Polyomavirus Nephropathy, comprising nine transplant centers in the United States and Europe. This study represents the largest systematic analysis of definitive PVN undertaken thus far. In a retrospective fashion, clinical data were collected from 192 patients and correlated with morphologic findings from index biopsies at the time of initial PVN diagnosis. Histologic features were centrally scored according to Banff guidelines, including additional semiquantitative histologic assessment of intrarenal polyomavirus replication/load levels. In-depth statistical analyses, including mixed effects repeated measures models and logistic regression, revealed two independent histologic variables to be most significantly associated with clinical presentation: intrarenal polyomavirus load levels and Banff interstitial fibrosis ci scores. These two statistically determined histologic variables formed the basis for the definition of three PVN classes that correlated strongest with three clinical parameters: presentation at time of index biopsy, serum creatinine levels/renal function over 24 months of follow-up, and graft failure. The PVN classes 1–3 as described here can easily be recognized in routine renal biopsy specimens. We recommend using this morphologic PVN classification scheme for diagnostic communication, especially at the time of index diagnosis, and in scientific studies to improve comparative data analysis.

scholarly journals Rainwater Harvesting for Agricultural Irrigation: An Analysis of Global Research

Water ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1320 ◽  
Author(s):  
Velasco-Muñoz ◽  
Aznar-Sánchez ◽  
Batlles-delaFuente ◽  
Fidelibus
Keyword(s):  
Rainwater Harvesting ◽  
Global Climate ◽  
The United States ◽  
Subject Area ◽  
Agricultural Irrigation ◽  
Systematic Analysis ◽  
Promising Alternative ◽  
Harvesting Systems ◽  
Scarce Water ◽  
Global Research

Within a context of scarce water resources for agriculture, rainwater harvesting constitutes a promising alternative that has been studied by different disciplines in recent years. This article analyses the dynamics of global research on rainwater harvesting for agricultural irrigation over the last two decades. To do this, qualitative systematic analysis and quantitative bibliometric analysis have been carried out. The results reveal that this line of research is becoming increasingly important within research on irrigation. Environmental sciences and agricultural and biological sciences are the most relevant subject areas. Agricultural Water Management, Physics and Chemistry of the Earth, and Irrigation and Drainage are the journals that have published the most articles on the subject. India, China, the United States (USA), South Africa, and the Netherlands are the countries that lead this line of research. Although significant progress has been made in this subject area, it is necessary to increase the number of studies on the capacity of rainwater harvesting systems to cover irrigation needs in different farming contexts, the factors that determine their adoption by farmers, the economic and financial feasibility of their implementation, and their contribution to mitigating global climate change.

scholarly journals Analytics for directed contact networks

2019 ◽  
Vol 4 (1) ◽  
Author(s):  
George Cybenko ◽  
Steve Huntsman
Keyword(s):  
Anomaly Detection ◽  
Markov Model ◽  
Social Networking ◽  
Data Reduction ◽  
Transportation Networks ◽  
Air Transportation ◽  
Temporal Networks ◽  
Contact Networks ◽  
Information Transfers ◽  
Specific Sequences

AbstractDirected contact networks (DCNs) are temporal networks that are useful for analyzing and modeling phenomena in transportation, communications, epidemiology and social networking. Specific sequences of contacts can underlie higher-level behaviors such as flows that aggregate contacts based on some notion of semantic and temporal proximity. We describe a simple inhomogeneous Markov model to infer flows and taint bounds associated with such higher-level behaviors, and also discuss how to aggregate contacts within DCNs and/or dynamically cluster their vertices. We provide examples of these constructions in the contexts of information transfers within computer and air transportation networks, thereby indicating how they can be used for data reduction and anomaly detection.

Sign in / Sign up

Export Citation Format

Share Document