scholarly journals Evolution and Construction Differentiation Pattern of African Railway Network

2021 ◽  
Vol 13 (24) ◽  
pp. 13728
Author(s):  
Yongshun Xie ◽  
Chengjin Wang
Keyword(s):  
Path Dependence ◽  
Spatial Organization ◽  
Spatial Differentiation ◽  
Technical Standards ◽  
Railway Network ◽  
Integration Model ◽  
Rail Network ◽  
Construction Market ◽  
Differentiation Pattern ◽  
Strategic Layout

Since the new century, countries in Africa have started a new round of rail network planning and construction which brings the completed different features together with the spatial organization of the railway network during the colonial period. Along with the strategic layout of “going out” with China’s railways, the organizational structure of the African railway network will make a tremendous change for the construction market, network organization, and gauge structure of the African railways. Based on the literature reviews, we analyzed and forecasted the evolution of railway network in Africa and discussed the spatial differentiation of the future construction market of the railways from the view of country and enterprise. The results show that the development of the African railway networks will experience three stages: 1850–1960, 1960–2010 and 2010–2050, and that the organization pattern of the African railway network has evolved from the “Hinterland-Port” model to the “Continental Integration” model. The development of railway technical standards tends to be integrated, the gauge type is changed from complicated to single, the gauge distribution is changed from broken to uniform. The contractor countries of the railway changed from English-French dominated to China dominated. The application of railway technical standards is influenced by technology dependence and path dependence and is mainly reflected in the two characteristics of “Chinese standard implantation” and “local standard retention”. The contractor enterprises of railway have a monopoly on the market of a country, CCECC and CRCC are leading, and the contractor enterprises are spatially characterized by four spatial distribution modes: single, continuous, jumping and comprehensive.

scholarly journals Infrastructure costs and benefits of European high-speed rail

2021 ◽  
Vol 1 (2) ◽  
pp. 47-53
Author(s):  
Nedžad Branković ◽  
Aida Kalem
Keyword(s):  
High Speed ◽  
New Technologies ◽  
Operational Parameters ◽  
Negative Effects ◽  
Railway Network ◽  
High Speed Rail ◽  
Rail Network ◽  
High Speed Trains ◽  
Conventional Rail ◽  
Ecologically Sustainable

The development of new technologies has significantly influenced railways modernization and has caused the appearance of high-speed rail which represent a safe, comfortable and ecologically sustainable way of transportation. The high-speed rail present a big step in a relation to conventional railways, where the biggest difference is speed which even entails a change of other organizational and operational parameters, better utilization of trains, higher performance of manpower and better service to users.  That is visible in many cities around the world where high-speed trains are used by billions of users. In the EU there is no unique high-speed railway network, besides that in many EU member countries various operational models are applied. The future of the high-speed railways market depends on political, economical and technical factors and challenges as high infrastructure costs, various rates of return on investment and the negative effects of economic crises. The main objective of the paper is to analyze infrastucture costs of high-speed rail in Europe and benefits such us  time savings, higher reliability, comfort, safety, reducing pollution and the release of capacity in the conventional rail network, roads and airport infrastructure.

scholarly journals Structural and functional analyses of photosystem II in the marine diatom Phaeodactylum tricornutum

2019 ◽  
Vol 116 (35) ◽  
pp. 17316-17322 ◽  
Author(s):  
Orly Levitan ◽  
Muyuan Chen ◽  
Xuyuan Kuang ◽  
Kuan Yu Cheong ◽  
Jennifer Jiang ◽  
...  
Keyword(s):  
Photosystem Ii ◽  
Spatial Organization ◽  
Higher Plants ◽  
Electron Tomography ◽  
Protein Complexes ◽  
Spatial Differentiation ◽  
Thylakoid Membranes ◽  
Marine Diatom ◽  
Red Algal ◽  
Antenna Proteins

A descendant of the red algal lineage, diatoms are unicellular eukaryotic algae characterized by thylakoid membranes that lack the spatial differentiation of stroma and grana stacks found in green algae and higher plants. While the photophysiology of diatoms has been studied extensively, very little is known about the spatial organization of the multimeric photosynthetic protein complexes within their thylakoid membranes. Here, using cryo-electron tomography, proteomics, and biophysical analyses, we elucidate the macromolecular composition, architecture, and spatial distribution of photosystem II complexes in diatom thylakoid membranes. Structural analyses reveal 2 distinct photosystem II populations: loose clusters of complexes associated with antenna proteins and compact 2D crystalline arrays of dimeric cores. Biophysical measurements reveal only 1 photosystem II functional absorption cross section, suggesting that only the former population is photosynthetically active. The tomographic data indicate that the arrays of photosystem II cores are physically separated from those associated with antenna proteins. We hypothesize that the islands of photosystem cores are repair stations, where photodamaged proteins can be replaced. Our results strongly imply convergent evolution between the red and the green photosynthetic lineages toward spatial segregation of dynamic, functional microdomains of photosystem II supercomplexes.

scholarly journals Application of Complex Network Principles to Key Station Identification in Railway Network Efficiency Analysis

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Li Wang ◽  
Min An ◽  
Limin Jia ◽  
Yong Qin
Keyword(s):  
Complex Network ◽  
Policy Development ◽  
Network Models ◽  
Efficiency Analysis ◽  
Physical Structure ◽  
Influential Factors ◽  
Clustering Coefficient ◽  
Network Efficiency ◽  
Railway Network ◽  
Rail Network

Network efficiency analysis becomes important in railways in order to contribute towards improving the safety and capacity of the rail network, making rail travel more attractive for passengers, and improving industry practice and informing policy development. However, a physical railway network structure is a complicated system, and the operation, maintenance, and management of such a network is a difficult task which may be affected by many influential factors. By using efficiency analysis technology for a railway network, combining physical structure with operation functions can help railway industry to optimize the railway network while improving its efficiency and reliability. This paper presents a new methodology based on complex network principles that combines the physical railway structure with railway operation strategy for a railway network efficiency analysis. In this method, two network models of railway physical and train flow networks are developed for the identification of key stations in the railway network based on network efficiency contribution in which the terms of degree, strength, betweenness, clustering coefficient, and a comprehensive factor are taken into consideration. Once the key stations have been identified and analysed, the railway network efficiency is then studied on the basis of selective and random modes of the station failures. A case study is presented in this paper to demonstrate the application of the proposed methodology. The results show that the identified key stations in the railway network play an important role in improving the overall railway network efficiency, which can provide useful information to railway designers, engineers, operators and maintainers to operate and maintain railway network effectively and efficiently.

scholarly journals Max-Plus Linear Equation System and Its Application on Railway Network System

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Andro Kurniawan ◽  
Ari Suparwanto
Keyword(s):  
Production Systems ◽  
Discrete Event ◽  
Equation System ◽  
Network System ◽  
Network Systems ◽  
Railway Network ◽  
Traffic Lights ◽  
Rail Network ◽  
Event System ◽  
Linear Equation System

Max-Plus algebra is the set of R U {-~} with R is the set of all real numbersthat are equipped with maximum operation and addition. Max-Plus algebra is able tomodel several types of Discrete Event System (DES) which are nonlinear in conventional algebra to be linear in Max-Plus algebra, so we can do further analysis of the system. Types of DES will be linear in the form of Max-Plus algebra which only synchronizes without any concurrency such as railway network systems, production systems, traffic lights, etc. This research discusses the application of the linear Max-Plus equation in the train schedules and involves synchronization between trains. The result of this study are obtained DAOP VI Yogyakarta rail network system model in the form of x(k + 1) = A otimes x (k) which is then used to determine the departure period and the time of initial train departure. The departure period is obtained from the eigenvalue (lambda) from the A matrix and the initial departure is obtained from the eigenvector corresponding to lambda. The calculation shows that the train departure period is T = 588 minutes.

scholarly journals Exploring the Hierarchical Structure of China’s Railway Network from 2008 to 2017

2018 ◽  
Vol 10 (9) ◽  
pp. 3173 ◽  
Author(s):  
Shiwei Lu ◽  
Yaping Huang ◽  
Zhiyuan Zhao ◽  
Xiping Yang
Keyword(s):  
Hierarchical Structure ◽  
High Speed ◽  
Spatial Organization ◽  
Average Distance ◽  
Detection Algorithm ◽  
Dominant Mode ◽  
Railway Network ◽  
High Speed Rail ◽  
Urban And Regional Development ◽  
Community Detection Algorithm

The analysis of transport networks is an important component of urban and regional development and planning. Based on the four main stages of China’s railway development from 2008 to 2017, this paper analyzes the hierarchical and spatial heterogeneity distribution of train flows. We found a high degree of spatial matching with the distribution of China’s main railway corridors. Then, using a classical community detection algorithm, this paper attempts to describe the functional structure and regional effects of China’s railway network. We also explore the impacts of construction policies and changes to train operations on the spatial organizing pattern and evolution of network hierarchies. The results of this empirical study reveal a clear pattern of independent communities, which in turn indicates the existence of a hierarchical structure in China’s railway network. The decreases in both the number of communities and average distance between community centers indicate that the newer high-speed rail services have shortened the connections between cities. In addition, the detected communities are inconsistent with China’s actual administrative divisions in terms of quantity and boundaries. The spatial spillover and segmentation effects cause the railway network in different regions to be self-contained. Finally, the detected communities in each stage can be divided into the categories of monocentric structure, dual-nuclei structure, and polycentric structure according to the number of extracted hubs. The polycentric structure is the dominant mode, which shows that the railway network has significant spatial dependence and a diversified spatial organization mode. This study has great significance for policymakers seeking to guide the future construction of high-speed rail lines and optimize national or regional railway networks.

scholarly journals Spatiotemporal Evolution and Influencing Factors of Ecological Civilization Construction in China

Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Mei Gai ◽  
Xiuqi Wang ◽  
Changli Qi
Keyword(s):  
Information Disclosure ◽  
Spatial Differentiation ◽  
Eastern Region ◽  
Analysis Tool ◽  
Government Information ◽  
Ecological Civilization ◽  
Regional Coordination ◽  
Evolution Characteristics ◽  
Differentiation Pattern ◽  
Threshold Regression Model

The construction of an ecological civilization is a strategic idea proposed based on the conditions of different countries and the laws governing social development. It is a new way to promote harmonious coexistence between humans and nature. Therefore, exploring the evolution characteristics and influence of ecological civilization in China is helpful for the country’s future development. This study uses the pentagon model, panel threshold regression model, and spatial analysis tool to explore the law of space-time differentiation and analyze regional coordination and ecological civilization construction in 31 provinces, cities, and autonomous regions in China from 2000 to 2018. During the study period, the construction of ecological civilization in China generally fluctuated; the spatial differentiation pattern of the eastern region was more developed than that of the central region, which was more developed than that of the western region. The regional coordination degree decreased in the order of east >central >northeast >west, and the degree of coordination in provinces and cities gradually shifted and finally accumulated to be reflected in the economy and environment in 2018. The most important factor affecting the development of ecological civilization was determined to be scientific research, followed by air quality and government information disclosure.

Welfare Economic Principles of (Urban) Rail Network Pricing

2016 ◽  
pp. 161-171
Author(s):  
Jörg Schimmelpfennig
Keyword(s):  
Consumer Surplus ◽  
Welfare Economic ◽  
Railway Network ◽  
Rail Network ◽  
Marginal Costs ◽  
Long Run ◽  
Pricing Rules ◽  
Urban Rail ◽  
Short Run ◽  
Definition Of

The purpose of this chapter is to rectify the at best unprofessional intermingling of objectives and constraints and present a proper theory of first-best and second-best pricing in urban rail networks. First, in view of the flaws of both Dupuit's – though nevertheless ingenious idea of – consumer surplus as well its cannibalized version found in most of today's economics textbooks, a proper definition of economic welfare resting on Hicks'sian variations instead is provided. It is used to derive efficient pricing rules that are subsequently applied to specific questions arising from running an urban railway network such as overcrowding, short-run versus long-run capacity or competing modes of transport like the private motor car. At the same time, another look is taken at economic costs, and in particular economic marginal costs, differing from commercial or accounting costs. Among other things, it is shown that even with commercial marginal costs being constant first-best pricing might not necessarily be incompatible with a zero-profit budget.

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