scholarly journals Dynamic Planning of Bicycle Stations in Dockless Public Bicycle-sharing System Using Gated Graph Neural Network

2021 ◽  
Vol 12 (2) ◽  
pp. 1-22
Author(s):  
Jianguo Chen ◽  
Kenli Li ◽  
Keqin Li ◽  
Philip S. Yu ◽  
Zeng Zeng

Benefiting from convenient cycling and flexible parking locations, the Dockless Public Bicycle-sharing (DL-PBS) network becomes increasingly popular in many countries. However, redundant and low-utility stations waste public urban space and maintenance costs of DL-PBS vendors. In this article, we propose a Bicycle Station Dynamic Planning (BSDP) system to dynamically provide the optimal bicycle station layout for the DL-PBS network. The BSDP system contains four modules: bicycle drop-off location clustering, bicycle-station graph modeling, bicycle-station location prediction, and bicycle-station layout recommendation. In the bicycle drop-off location clustering module, candidate bicycle stations are clustered from each spatio-temporal subset of the large-scale cycling trajectory records. In the bicycle-station graph modeling module, a weighted digraph model is built based on the clustering results and inferior stations with low station revenue and utility are filtered. Then, graph models across time periods are combined to create a graph sequence model. In the bicycle-station location prediction module, the GGNN model is used to train the graph sequence data and dynamically predict bicycle stations in the next period. In the bicycle-station layout recommendation module, the predicted bicycle stations are fine-tuned according to the government urban management plan, which ensures that the recommended station layout is conducive to city management, vendor revenue, and user convenience. Experiments on actual DL-PBS networks verify the effectiveness, accuracy, and feasibility of the proposed BSDP system.

2020 ◽  
Vol 4 (1) ◽  
Author(s):  
Daniel M. Cáceres ◽  
Esteban Tapella ◽  
Diego A. Cabrol ◽  
Lucrecia Estigarribia

Argentina is experiencing an expansion of soya and maize cultivation that is pushing the agricultural frontier over areas formerly occupied by native Chaco forest. Subsistance farmers use this dry forest to raise goats and cattle and to obtain a broad range of goods and services. Thus, two very different and non-compatible land uses are in dispute. On the one hand subsistance farmers fostering an extensive and diversified forest use, on the other hand, large-scale producers who need to clear out the forest to sow annual crops in order to appropriate soil fertility. First, the paper looks at how these social actors perceive Chaco forest, what their interests are, and what kind of values they attach to it. Second, we analyze the social-environmental conflicts that arise among actors in order to appropriate forest’s benefits. Special attention is paid to the role played by the government in relation to: (a) how does it respond to the demands of the different sectors; and (b) how it deals with the management recommendations produced by scientists carrying out social and ecological research. To put these ideas at test we focus on a case study located in Western Córdoba (Argentina), where industrial agriculture is expanding at a fast pace, and where social actors’ interests are generating a series of disputes and conflicts. Drawing upon field work, the paper shows how power alliances between economic and political powers, use the institutional framework of the State in their own benefit, disregarding wider environmental and social costs. 


2019 ◽  
Vol 12 (3) ◽  
pp. 77-85
Author(s):  
L. D. Kapranova ◽  
T. V. Pogodina

The subject of the research is the current state of the fuel and energy complex (FEC) that ensures generation of a significant part of the budget and the innovative development of the economy.The purpose of the research was to establish priority directions for the development of the FEC sectors based on a comprehensive analysis of their innovative and investment activities. The dynamics of investment in the fuel and energy sector are considered. It is noted that large-scale modernization of the fuel and energy complex requires substantial investment and support from the government. The results of the government programs of corporate innovative development are analyzed. The results of the research identified innovative development priorities in the power, oil, gas and coal sectors of the fuel and energy complex. The most promising areas of innovative development in the oil and gas sector are the technologies of enhanced oil recovery; the development of hard-to-recover oil reserves; the production of liquefied natural gas and its transportation. In the power sector, the prospective areas are activities aimed at improving the performance reliability of the national energy systems and the introduction of digital technologies. Based on the research findings, it is concluded that the innovation activities in the fuel and energy complex primarily include the development of new technologies, modernization of the FEC technical base; adoption of state-of-the-art methods of coal mining and oil recovery; creating favorable economic conditions for industrial extraction of hard-to-recover reserves; transition to carbon-free fuel sources and energy carriers that can reduce energy consumption and cost as well as reducing the negative FEC impact on the environment.


Author(s):  
Angela Dranishnikova

In the article, the author reflects the existing problems of the fight against corruption in the Russian Federation. He focuses on the opacity of the work of state bodies, leading to an increase in bribery and corruption. The topic we have chosen is socially exciting in our days, since its significance is growing on a large scale at all levels of the investigated aspect of our modern life. Democratic institutions are being jeopardized, the difference in the position of social strata of society in society’s access to material goods is growing, and the state of society is suffering from the moral point of view, citizens are losing confidence in the government, and in the top officials of the state.


Author(s):  
Morten Egeberg ◽  
Jarle Trondal

Chapter 8 draws attention to meta-governance and how the governing of reforms is affected by how reform processes are organized. The chapter asks how reformers can ensure support for large-scale reforms that are likely to attract profound resistance. The focal point of the chapter is a study of geographical decentralization of central government agencies. The chapter argues that successful meta-governance can be provided for by careful organization of the reform process. The empirical case studied is a large-scale relocation of government agencies in Norway during the early 2000s. In carrying out this reform, the government succeeded against the odds. Most importantly, research has revealed huge constraints on the instrumental control of large-scale reforms in general and of geographical relocation of organizations in particular. Yet, this chapter shows that large-scale reforms can be successfully achieved through careful crafting of the reform organization.


2021 ◽  
Vol 7 (2) ◽  
pp. 105
Author(s):  
Vinodhini Thiyagaraja ◽  
Robert Lücking ◽  
Damien Ertz ◽  
Samantha C. Karunarathna ◽  
Dhanushka N. Wanasinghe ◽  
...  

Ostropales sensu lato is a large group comprising both lichenized and non-lichenized fungi, with several lineages expressing optional lichenization where individuals of the same fungal species exhibit either saprotrophic or lichenized lifestyles depending on the substrate (bark or wood). Greatly variable phenotypic characteristics and large-scale phylogenies have led to frequent changes in the taxonomic circumscription of this order. Ostropales sensu lato is currently split into Graphidales, Gyalectales, Odontotrematales, Ostropales sensu stricto, and Thelenellales. Ostropales sensu stricto is now confined to the family Stictidaceae, which includes a large number of species that are poorly known, since they usually have small fruiting bodies that are rarely collected, and thus, their taxonomy remains partly unresolved. Here, we introduce a new genus Ostropomyces to accommodate a novel lineage related to Ostropa, which is composed of two new species, as well as a new species of Sphaeropezia, S. shangrilaensis. Maximum likelihood and Bayesian inference analyses of mitochondrial small subunit spacers (mtSSU), large subunit nuclear rDNA (LSU), and internal transcribed spacers (ITS) sequence data, together with phenotypic data documented by detailed morphological and anatomical analyses, support the taxonomic affinity of the new taxa in Stictidaceae. Ancestral character state analysis did not resolve the ancestral nutritional status of Stictidaceae with confidence using Bayes traits, but a saprotrophic ancestor was indicated as most likely in a Bayesian binary Markov Chain Monte Carlo sampling (MCMC) approach. Frequent switching in nutritional modes between lineages suggests that lifestyle transition played an important role in the evolution of this family.


Author(s):  
Pamela Wiener ◽  
Christelle Robert ◽  
Abulgasim Ahbara ◽  
Mazdak Salavati ◽  
Ayele Abebe ◽  
...  

Abstract Great progress has been made over recent years in the identification of selection signatures in the genomes of livestock species. This work has primarily been carried out in commercial breeds for which the dominant selection pressures, are associated with artificial selection. As agriculture and food security are likely to be strongly affected by climate change, a better understanding of environment-imposed selection on agricultural species is warranted. Ethiopia is an ideal setting to investigate environmental adaptation in livestock due to its wide variation in geo-climatic characteristics and the extensive genetic and phenotypic variation of its livestock. Here, we identified over three million single nucleotide variants across 12 Ethiopian sheep populations and applied landscape genomics approaches to investigate the association between these variants and environmental variables. Our results suggest that environmental adaptation for precipitation-related variables is stronger than that related to altitude or temperature, consistent with large-scale meta-analyses of selection pressure across species. The set of genes showing association with environmental variables was enriched for genes highly expressed in human blood and nerve tissues. There was also evidence of enrichment for genes associated with high-altitude adaptation although no strong association was identified with hypoxia-inducible-factor (HIF) genes. One of the strongest altitude-related signals was for a collagen gene, consistent with previous studies of high-altitude adaptation. Several altitude-associated genes also showed evidence of adaptation with temperature, suggesting a relationship between responses to these environmental factors. These results provide a foundation to investigate further the effects of climatic variables on small ruminant populations.


Diversity ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 109 ◽  
Author(s):  
Rebecca T. Kimball ◽  
Carl H. Oliveros ◽  
Ning Wang ◽  
Noor D. White ◽  
F. Keith Barker ◽  
...  

It has long been appreciated that analyses of genomic data (e.g., whole genome sequencing or sequence capture) have the potential to reveal the tree of life, but it remains challenging to move from sequence data to a clear understanding of evolutionary history, in part due to the computational challenges of phylogenetic estimation using genome-scale data. Supertree methods solve that challenge because they facilitate a divide-and-conquer approach for large-scale phylogeny inference by integrating smaller subtrees in a computationally efficient manner. Here, we combined information from sequence capture and whole-genome phylogenies using supertree methods. However, the available phylogenomic trees had limited overlap so we used taxon-rich (but not phylogenomic) megaphylogenies to weave them together. This allowed us to construct a phylogenomic supertree, with support values, that included 707 bird species (~7% of avian species diversity). We estimated branch lengths using mitochondrial sequence data and we used these branch lengths to estimate divergence times. Our time-calibrated supertree supports radiation of all three major avian clades (Palaeognathae, Galloanseres, and Neoaves) near the Cretaceous-Paleogene (K-Pg) boundary. The approach we used will permit the continued addition of taxa to this supertree as new phylogenomic data are published, and it could be applied to other taxa as well.


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2582 ◽  
Author(s):  
Samuel Lotsu ◽  
Yuichiro Yoshida ◽  
Katsufumi Fukuda ◽  
Bing He

Confronting an energy crisis, the government of Ghana enacted a power factor correction policy in 1995. The policy imposes a penalty on large-scale electricity users, namely, special load tariff (SLT) customers of the Electricity Company of Ghana (ECG), whose power factor is below 90%. This paper investigates the impact of this policy on these firms’ power factor improvement by using panel data from 183 SLT customers from 1994 to 1997 and from 2012. To avoid potential endogeneity, this paper adopts a regression discontinuity design (RDD) with the power factor of the firms in the previous year as a running variable, with its cutoff set at the penalty threshold. The result shows that these large-scale electricity users who face the penalty because their power factor falls just short of the threshold are more likely to improve their power factor in the subsequent year, implying that the power factor correction policy implemented by Ghana’s government is effective.


2007 ◽  
Vol 3 ◽  
pp. 193-197 ◽  
Author(s):  
Kou Amano ◽  
Hiroaki Ichikawa ◽  
Hidemitsu Nakamura ◽  
Hisataka Numa ◽  
Kaoru Fukami-Kobayashi ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document