Rail systems delivery - long term thinking for a long term environment

2004 ◽  
Author(s):  
S. Daw
Keyword(s):  
Rail Systems

Urban Rail Development in China

2012 ◽  
Vol 2275 (1) ◽  
pp. 49-57 ◽  
Author(s):  
Andrew Salzberg ◽  
Shomik Mehndiratta ◽  
Zhi Liu
Keyword(s):  
Large Scale ◽  
Economic Benefits ◽  
Urban Transport ◽  
Transit Oriented Development ◽  
Rail Systems ◽  
Urban Rail ◽  
Analytical Work ◽  
Metro Systems ◽  
The City

This paper provides an overview of the recent development of urban rail systems in Chinese cites and the challenges ahead. China is set to become the world leader in length of metro lines in operation in the near to medium term. In view of the large scale of this investment, a focus on the overall economic and financial viability of these systems is needed. On the basis of analytical work supporting a project investment in the city of Kunming and a study tour of urban rail systems in China, this paper highlights four areas believed to be crucial in meeting these objectives: integration of new metro systems with existing systems of public transport, a supportive overall urban transport policy, transit-oriented development, and long-term financial sustainability. The conclusion is that in all of these areas, China possesses tools that may enable the program to succeed if they are used effectively and in concert. Any issues appear to result from a lack of attention to these four areas and from a managerial focus on ensuring the completion of the construction program above all other concerns. The RMB 1 trillion investment in urban rail construction under way in China needs to be a catalyst for joint action on the issues identified in this paper (RMB 1 is approximately US$0.15). Otherwise, Chinese cities may be left with an investment that carries large long-term costs and does not deliver the crucial economic benefits expected.

scholarly journals Settlement characteristics of major infrastructures in Shanghai

2015 ◽  
Vol 372 ◽  
pp. 475-479
Author(s):  
X. Jiao ◽  
X. X. Yan ◽  
H. M. Wang
Keyword(s):  
Critical Infrastructure ◽  
Monitoring Network ◽  
Ground Subsidence ◽  
Rail Transportation ◽  
Rail Systems ◽  
Early Warning Mechanism ◽  
Geological Conditions ◽  
The Impact ◽  
Settlement Monitoring

Abstract. Critical infrastructures in Shanghai have undergone uneven settlement since their operation, which plays an important role in affecting the security of Shanghai. This paper, taking rail transportation as example, investigates settlement characteristics and influencing factors of this linear engineering, based on long-term settlement monitoring data. Results show that rail settlement is related to geological conditions, regional ground subsidence, surrounding construction activities and structural differences in the rail systems. In order to effectively decrease the impact of regional ground subsidence, a monitoring and early-warning mechanism for critical infrastructure is established by the administrative department and engineering operators, including monitoring network construction, settlement monitoring, information sharing, settlement warning, and so on.

Turf Track for Light Rail Systems

2012 ◽  
Vol 2275 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Margarita Novales ◽  
Emilio Conles
Keyword(s):  
Fine Particles ◽  
Light Rail ◽  
Heat Island ◽  
Construction Costs ◽  
Right Of Way ◽  
Rail Systems ◽  
Rainwater Management ◽  
Visual Impact ◽  
The City

Light rail systems are experiencing a revival in several countries. In many new and refurbished networks, turf—or grass—tracks are being used as a means to get a reserved right-of-way that entails enhancements in the city landscape. These tracks can facilitate acceptance of the system by citizens and politicians. The visual impact of turf tracks is only one of their many advantages, which are discussed in this paper. Among the advantages are a reduction in noise and suspended fine particles, the “green lung” effect, improvements in rainwater management and heat island mitigation, and a decrease in the operational and construction costs of the system. This solution has some inconveniences, such as the need for maintenance of vegetation and for rail–environment separation, and additional precautions must be taken to ensure good performance in the long term. There are also limitations, such as the inability of buses and emergency vehicles to travel on turf tracks; additional problems in case of derailment; and possible operational incidents due to irrigation, mowing, and the combination of vegetation waste and sand. This paper focuses on explaining the advantages, inconveniences, and limitations. The intent is to provide a better understanding of the solution and to simplify the decision of whether to use turf tracks in a new light rail system.

Competition Into Brazilian and North American Freight Rail Systems: A Comparative Regulatory Assessment

2018 ◽  
Author(s):  
Fábio C. Barbosa
Keyword(s):  
United States ◽  
Private Sector ◽  
North American ◽  
Operational Environment ◽  
Network Efficiency ◽  
Technical Literature ◽  
Rail Network ◽  
Rail System ◽  
Rail Systems

Competition is the driving force of any economic system, as it creates a challenging environment for service suppliers to provide affordable and reliable services to customers. Rail systems are an important element of the logistic chain, as they provide a unique service category (generally transporting large volumes at low unit costs) to shippers that otherwise would not be serviced by other modes — the so called captive shippers. In this scenario, competition is essential to guarantee the required service levels (availability and reliability), followed by competitive rates, which ultimately may influence shippers’ business competitiveness, both regionally and globally. Brazil and some North American countries (Canada, Mexico and United States), have a common feature, i.e. continental territories allied with the economic exploitation of bulky activities (industrial, mineral and agricultural), and, hence, depend strongly on heavy haul rail systems. These countries have been performing a continuous effort on improving competition practices into their rail systems, which are translated into important, and sometimes controversial, regulatory measures. These initiatives require a tenuous equilibrium, as they are supposed to provide the required competitive service at affordable rates for shippers, as well as a sustainable (financial and operational) environment to rail carriers, to guarantee the required return on long term investments and avoid compromising medium and long term rail network efficiency. This challenging task for rail market stakeholders (rail carriers, shippers and regulators) is far from a consensus. Rail companies claim that, as a capital intensive sector, governmental regulatory intervention into the rail system may inhibit their ability to invest the required funds to provide and expand rail capacity, as well as the maintenance of the required safety levels. Shippers, on the other hand, state that rail systems operate within a strong market concentration (originally formatted or due to subsequent merges and acquisitions) that give some rail carriers a disproportionate market power, that resembles a monopoly, which ultimately leaves a significant contingent of the so called captive shippers with just one freight rail carrier option, sometimes subjected to excessive rates, and, in some special instances (into offer restricted rail markets, for example), are responsible for the unavailability of rail services into the required volumes. In this context, there is currently a controversial debate regarding the effectiveness of competitive regulatory remedies into freight rail systems. This debate includes both market oriented rail systems (Canadian and U.S.), as well as rail contractual granted ones (Brazilian and Mexican). In the formers, the systems are mostly owned and operated by the private sector, and inter and intra modal options may theoretically provide the required competition level, while in the latter, rail systems have been broken into separate pieces and granted to the private sector under a concession arrangement, followed by an exclusive right to serve their territories, with trackage rights provisions, to be exerted by third parties, under previously defined circumstances and subjected to contractual agreements among rail operators. In both systems, competitive regulatory actions may be desirable and effective, as far as they may address the technical-operational-economic boundary conditions of each particular rail system. This work is supposed to present, into a review format, sourced from an extensive research into available international technical literature, and gathered as a unique document, an overview of the Brazilian and North American freight rail competition scenario, followed by a technical and unbiased effectiveness’ assessment of current (existing) and proposed competitive regulatory freight rail initiatives into Brazil, Canada, Mexico and United States, highlighting their strengths and eventually their weaknesses.

Therapy and prevention for mental health: What if mental diseases are mostly not brain disorders?

2019 ◽  
Vol 42 ◽  
Author(s):  
John P. A. Ioannidis
Keyword(s):  
Mental Health ◽  
Mental Disease ◽  
Brain Disorders ◽  
Social Stressors ◽  
Labor Education ◽  
Mental Diseases ◽  
Long Term Follow Up ◽  
Political Decisions

AbstractNeurobiology-based interventions for mental diseases and searches for useful biomarkers of treatment response have largely failed. Clinical trials should assess interventions related to environmental and social stressors, with long-term follow-up; social rather than biological endpoints; personalized outcomes; and suitable cluster, adaptive, and n-of-1 designs. Labor, education, financial, and other social/political decisions should be evaluated for their impacts on mental disease.

Conceptual short-term memory (CSTM) supports core claims of Christiansen and Chater

2016 ◽  
Vol 39 ◽  
Author(s):  
Mary C. Potter
Keyword(s):  
Working Memory ◽  
Rapid Serial Visual Presentation ◽  
Language Comprehension ◽  
Short Term Memory ◽  
Visual Presentation ◽  
Long Term Memory ◽  
Short Term ◽  
Term Memory ◽  
Use Of Knowledge

AbstractRapid serial visual presentation (RSVP) of words or pictured scenes provides evidence for a large-capacity conceptual short-term memory (CSTM) that momentarily provides rich associated material from long-term memory, permitting rapid chunking (Potter 1993; 2009; 2012). In perception of scenes as well as language comprehension, we make use of knowledge that briefly exceeds the supposed limits of working memory.

Brief summary of Kleť photographic search programme for minor planets

1999 ◽  
Vol 173 ◽  
pp. 189-192
Author(s):  
J. Tichá ◽  
M. Tichý ◽  
Z. Moravec
Keyword(s):  
Ccd Camera ◽  
Minor Planet ◽  
Minor Planets ◽  
Main Belt

AbstractA long-term photographic search programme for minor planets was begun at the Kleť Observatory at the end of seventies using a 0.63-m Maksutov telescope, but with insufficient respect for long-arc follow-up astrometry. More than two thousand provisional designations were given to new Kleť discoveries. Since 1993 targeted follow-up astrometry of Kleť candidates has been performed with a 0.57-m reflector equipped with a CCD camera, and reliable orbits for many previous Kleť discoveries have been determined. The photographic programme results in more than 350 numbered minor planets credited to Kleť, one of the world's most prolific discovery sites. Nearly 50 per cent of them were numbered as a consequence of CCD follow-up observations since 1994.This brief summary describes the results of this Kleť photographic minor planet survey between 1977 and 1996. The majority of the Kleť photographic discoveries are main belt asteroids, but two Amor type asteroids and one Trojan have been found.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

Sign in / Sign up

Export Citation Format

Share Document