THE ISSUES OF TRAIN SCHEDULE FULFILLMENT STABILITY IMPROVEMENT

2018 ◽  
pp. 59-70
Author(s):  
Alexey Kotenko ◽  
Andrey Grachev ◽  
Anastasiya Gogoleva ◽  
Timofey Shmanev
Keyword(s):  
Practical Importance ◽  
Efficiency Coefficient ◽  
Computational Theory ◽  
Individual Basis ◽  
Passenger Traffic ◽  
Train Routing ◽  
Schedule Stability ◽  
The Stability ◽  
Interval Efficiency ◽  
Capacity Efficiency

Objective: At present the majority of railway lines experiences serious difficulties in handling of the increased flow of freight trains with considerable amount of passenger traffic. In view of this there is a necessity to improve the level of train schedule stability by creating certain time slacks in it, which make it possible to eliminate errors. Methods: The methods of simulation, computational theory and construction of a train schedule graph were applied. Results: The method of train routing was developed on the basis of simulation of schedule configuration. The characteristics of schedule configuration and conditions of its creation were presented. The influence of trainhandling capacity efficiency coefficient on the choice of a configured train routing diagram was studied, as well as one of the vital factors, causing degradation of train schedule fulfillment stability – disagreement in train traffic. It was shown that in case of selecting a configuration it was necessary to increase the headway between consecutive trains after a bunch of trains, and if train overtaking is inevitable – to use the time of extra removal. In order to eliminate the consequences of disagreement in train traffic, it was proposed to increase intervals not between all trains, but to compensate the disagreement after passage of a number of trains, the latter should be specified on an individual basis. The assessment of compensating interval efficiency was fulfilled by means of removal coefficient calculation for different conditions on three options. It was concluded that the compensating interval not only reduces disagreement impact, but also improves train-handling capacity. The example of train schedule stability improvement was considered on the basis of applying configurations at “Malaya Vishera – Bologoye” section on down trains within the period of time from 11.30 pm to 7.30 am. Practical importance: Application of configurations makes it possible to achieve higher implementable levels of speed and train-handling capacity, leads to the detection of time slacks and time buffers, which considerably increase train schedule stability and, consequently, the stability of its fulfillment.

scholarly journals Performance Evaluation of Heading-and-Winning Machines in the Conditions of Potash Mines

2021 ◽  
Vol 11 (8) ◽  
pp. 3444
Author(s):  
Sergey A. Lavrenko ◽  
Dmitriy I. Shishlyannikov
Keyword(s):  
Energy Efficiency ◽  
Experimental Studies ◽  
Efficiency Coefficient ◽  
Mechanized Method ◽  
Methodological Approaches ◽  
The Stability ◽  
Technical Solutions ◽  
Potash Mine ◽  
Complex Indicators ◽  
Potassium Magnesium

The authors focus on the process of potash ore production by a mechanized method. They show that currently there are no approved procedures for assessing the performance of heading-and-winning machines operating in the conditions of potash mines. This causes difficulties in determining the field of application of heading-and-winning machines, complicates the search for implicit technical solutions for the modernisation of existing models of mining units, prohibits real-time monitoring of the stability of stope-based technological processes and makes it difficult to assess the performance of the services concerning mining enterprises. The work represents an aggregate assessment of the performance of heading-and-winning machines for potash mines by determining complex indicators describing the technological and technical levels of organising the work in stopes. Such indicators are the coefficients of productivity and energy efficiency, respectively. Experimental studies have been carried out in the conditions of the potash mine of the Verkhnekamskoye potassium-magnesium salt deposit to assess the performance of the latest and most productive Ural-20R heading-and-winning machines manufactured in Russia. Using the above methodological approaches, this paper shows that the unsatisfactory technological performance of the studied machine is due to the low productivity of the mine district transport. The average productivity coefficient was 0.29. At the same time, high values of the energy efficiency coefficient show that the productivity of the machine is on par with design conditions.

Energetics and Structural Effects of Boron Additive to Intermetallic Compound: γ-Tial

1990 ◽  
Vol 213 ◽  
Author(s):  
P.K. Khowash ◽  
D.L. Price ◽  
B.R. Cooper
Keyword(s):  
Intermetallic Compound ◽  
Total Energy ◽  
Site Selection ◽  
Lattice Structure ◽  
Practical Importance ◽  
The Difference ◽  
The Stability ◽  
Experimental Values ◽  
And Behavior ◽  
Good Agreement

ABSTRACTImproving the low temperature ductility of the intermetallic compound γ - TiAl by alloying with small concentrations of an additive is of great practical importance. The difference in site selection energy of the additive plays an important role in the stability and behavior of the alloy. For boron in L10 TiAl, we have calculated the site selection energy using linearized combination of muffin-tin orbitals (LMTO) total energy calculations. For pure γ - TiAl, we found the equilibrium lattice structure by minimizing the total energy, and obtained good agreement with the experimental values. With the introduction of boron, a relaxation of the lattice around the boron additive is expected. For boron additives, we have calculated the forces on each atom leading to the minimization of the total energy as a function of the ionic positions in order to obtain the “true” stable structure of the alloy.

scholarly journals Genotype x Environment Interaction in Maritime Pine Families in Galicia, Northwest Spain

2004 ◽  
Vol 53 (1-6) ◽  
pp. 175-182 ◽  
Author(s):  
R. Zas ◽  
E. Merlo ◽  
J. Fernández-López
Keyword(s):  
Variance Component ◽  
Practical Importance ◽  
Genetic Correlations ◽  
Maritime Pine ◽  
Environment Interaction ◽  
Nw Spain ◽  
Genotype X Environment ◽  
Pinus Pinaster Ait ◽  
Sib Families ◽  
The Stability

SummaryThe magnitude and practical importance of family x site interactions for growth and form traits in maritime pine (Pinus pinaster Ait.) breeding in the coastal area of Galicia (NW Spain) were analysed using several different techniques. Data were from 58 8-yr-old half-sib families planted across four sites. The analysis of variance and the ratio of interaction to family variance component showed the interactions to be quantitatively important for several traits, especially for volume and straightness. Genetic correlations between the same trait at different sites were moderate and highly variable, especially for certain pairs of sites. The results indicated that interactions are a consequence of few highly interactive families that may be particularly sensitive to environmental variation. The removal of these families from the breeding program appeared as an effective strategy to solve the interactions. Results are discussed in relation to the stability parameter considered to identify the most unstable progenies.

scholarly journals The physiological butyrylcholinesterase tetramer is a dimer of dimers stabilized by a superhelical assembly

2018 ◽  
Author(s):  
Miguel Ricardo Leung ◽  
Laura S. van Bezouwen ◽  
Lawrence M. Schopfer ◽  
Joel L. Sussman ◽  
Israel Silman ◽  
...  
Keyword(s):  
Practical Importance ◽  
Residence Times ◽  
Catalytic Domains ◽  
Polyproline Ii ◽  
Cryo Electron Microscopy ◽  
Tetramerization Domain ◽  
Polyproline Ii Helix ◽  
Quaternary Structures ◽  
The Stability ◽  
And Function

AbstractThe quaternary structures of the cholinesterases, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), are essential for their localisation and function. Of practical importance, BChE is a promising therapeutic candidate for intoxication by organophosphate nerve agents and insecticides, and for detoxification of addictive substances. Efficacy of the recombinant enzyme hinges on its having a long circulatory half-life; this, in turn, depends strongly on its ability to tetramerize. Here, we used cryo-electron microscopy (cryo-EM) to determine the structure of the highly glycosylated native BChE tetramer purified from human plasma at 5.7 Å. Our structure reveals that the BChE tetramer is organised as a staggered dimer of dimers. Tetramerization is mediated by assembly of the C-terminal tryptophan amphiphilic tetramerization (WAT) helices from each subunit as a superhelical assembly around a central anti-parallel polyproline II helix (PRAD). The catalytic domains within a dimer are asymmetrically linked to the WAT/PRAD. In the resulting arrangement, the tetramerization domain is largely shielded by the catalytic domains, which may contribute to the stability of the HuBChE tetramer. Our cryo-EM structure reveals the basis for assembly of the physiological tetramers, and has implications for the therapeutic applications of HuBChE. This mode of tetramerization is seen only in the cholinesterases, and may provide a promising template for designing other proteins with improved circulatory residence times.

scholarly journals Reconstruction of a railway station under changing conditions in passenger traffic

2021 ◽  
pp. 82-106
Author(s):  
Oksana D. POKROVSKAY ◽  
◽  
Anna N. ILLARIONOVA ◽  
Keyword(s):  
Practical Importance ◽  
Track Length ◽  
General Systems Theory ◽  
Economic Calculation ◽  
Passenger Traffic ◽  
General Systems ◽  
Organize Work ◽  
Railway Passenger ◽  
The Cost ◽  
To Receive

Objective: Drawing on the study of the situation in railway passenger traffic, to propose measures for the reconstruction of station M of the Murmansk transport hub and perform a consolidated estimate of the cost of implementing the proposed measures. Methods: The means and methods of general systems theory, system and economic analysis, terminalistics, logistics and management of the ope- rational work of railways are used. Results: Based on the results of the economic calculation, it was concluded that it is necessary to reconstruct the exhibition track N 2 to receive passenger trains of 25 cars and organize work with double-deck cars. A consolidated estimate of the cost of building an exhibition track N 2 has been made. Practical importance: Thanks to the increase in the useful track length, new opportunities will be opened for the development of promising passenger traffic at the station in question and, consequently, for an increase in the profit of the Russian Railways company. The results obtained can be applied in the implementation of the development concept of the Mur- mansk transport hub, in the design of individual elements and devices of the railway hub, as well as in the optimization of passenger service technology.

A Comprehensive Stability Criterion for Forced Vibrations in Nonlinear Systems

1953 ◽  
Vol 20 (1) ◽  
pp. 9-12
Author(s):  
K. Klotter ◽  
E. Pinney
Keyword(s):  
Differential Equation ◽  
Nonlinear Systems ◽  
Stability Criterion ◽  
Practical Importance ◽  
Nonlinear Function ◽  
Forced Vibrations ◽  
Maximum Value ◽  
The Stability

Abstract This paper deals with the forced vibrations described by the differential equation a q .. + c q + c Φ ( q , q . ) = P cos Ω t wherein Φ denotes a nonlinear function of q and/or q̇. It presents a criterion for determining their stability. It is shown that under very weak restrictions, which equivalently means, for a large variety of cases (including all of practical importance) the stability depends on the sign of ∂q*/∂P (q* denoting the maximum value of q(t) within a period). The motion is stable if this derivative is positive; it is unstable if it is negative.

Efficient Formulations and Decomposition Approaches for Power Peak Reduction in Railway Traffic via Timetabling

2021 ◽  
Author(s):  
Andreas Bärmann ◽  
Alexander Martin ◽  
Oskar Schneider
Keyword(s):  
Power Supply ◽  
Benders Decomposition ◽  
Optimization Models ◽  
Peak Reduction ◽  
Efficient Operation ◽  
Passenger Traffic ◽  
Railway Traffic ◽  
Power Peak ◽  
Railway Passenger ◽  
The Stability

Over the last few years, optimization models for the energy-efficient operation of railway traffic have received more and more attention, particularly in connection with timetable design. In this work, we study the effect of load management via timetabling. The idea is to consider trains as time-flexible consumers in the railway power supply network and to use slight shifts in the departure times from the stations to avoid too many simultaneous departures. This limits peak consumption and can help to improve the stability of the power supply. To this end, we derive efficient formulations for the problem of an optimal timetable adjustment based on a given timetable draft, two of which even allow for totally unimodular polyhedral descriptions. The proper choice of the objective function allows the incorporation of the priorities of either the train operating companies or the infrastructure manager. These include the avoidance of large peaks in average or instantaneous consumption and the improved use of recuperated braking energy. To solve the arising optimization models efficiently, we develop specially tailored exact Benders decomposition schemes that allow for the computation of high-quality solutions within a very short time. In an extensive case study for German railway passenger traffic, we show that our methods are capable of solving the problem on a nationwide scale. We see that the optimal adjustment of timetables entails a tremendous potential for reducing energy consumption.

scholarly journals Stability of network centrality measures: a numerical study

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Orsolya Kardos ◽  
András London ◽  
Tamás Vinkó
Keyword(s):  
Numerical Study ◽  
Practical Importance ◽  
Centrality Measures ◽  
Network Stability ◽  
Signal Process ◽  
Node Centrality ◽  
Relevant Task ◽  
The Stability ◽  
Definition Of ◽  
Graph Perturbation

AbstractIdentifying key actors or nodes in a network is a relevant task regarding many applications. In general, the real-valued function that evaluates the nodes is called node centrality measure. Performing a relevance-based ranking on the list of nodes is also of high practical importance, since the most central nodes by a measure usually provide the highest contribution in explaining the behavior of the whole network. Stability of centrality measures against graph perturbation is an important concept, especially in the analysis of real world—often noise contaminated—datasets from different domains. In this paper, with the utilization of the formal definition of stability introduced by Segarra and Ribeiro (IEEE Trans Signal Process 64(3):543–555, 2015), we discuss three main perturbation categories and experimentally analyze the stability of several node centrality measures.

Stability Criteria for Standing and Spinning Waves in Annular Combustors

2015 ◽  
Author(s):  
Giulio Ghirardo ◽  
Matthew P. Juniper ◽  
Jonas P. Moeck
Keyword(s):  
Gas Turbines ◽  
Practical Importance ◽  
Industrial Applications ◽  
Describing Function ◽  
Combustion Chambers ◽  
Rotationally Symmetric ◽  
Annular Combustor ◽  
Flame Describing Function ◽  
The Stability ◽  
Future Direction

Rotationally symmetric annular combustors are of practical importance because they generically resemble combustion chambers in gas turbines and aeroengines, in which thermoacoustically driven oscillations are a major concern. We focus on thermoacoustic oscillations of azimuthal type, neglect the effect of the transverse acoustic velocity in the azimuthal direction, and model the heat release rate as being dependent only on the pressure in the combustion chamber. We study the dynamics of the annular combustor with a finite number of compact flames equi-spaced along the annulus, and characterise the flames’ response with a describing function. We discuss with broad generality the existence, amplitudes and the stability of standing and spinning waves, as a function of: 1) the number of the burners; 2) the damping in the chamber; 3) the flame describing function. These have implications on industrial applications, the future direction of investigations, and for what to look for in experimental data. We then present as an example of application the first theoretical study of triggering in annular combustors, and show that rotationally symmetric annular chambers can experience stable standing solutions.

scholarly journals Akty zarządzania dobrami doczesnymi

2017 ◽  
Vol 58 (3) ◽  
pp. 105
Author(s):  
LUCJAN ŚWITO
Keyword(s):  
Canon Law ◽  
Practical Importance ◽  
Legal Action ◽  
Legal Practice ◽  
Pope John Paul Ii ◽  
Code Of Canon Law ◽  
Great Practical Importance ◽  
John Paul Ii ◽  
The Stability

The Code of Canon Law (Corpus Iuris Canonici, CIC), in its version enacted by Pope John Paul II, employs diverse terminology when refer- ring to acts of administration of goods. Can. 1277 of CIC refers to “acts of administration which are more important” and “acts of extraordinary administration”, while the provision of 1281 §1 and §2 of CIC points out the dierence between “acts of ordinary administration” and “acts which exceed the limit and manner of ordinary administration”. Although the terminology adopted in the Code of Canon Law clearly marks the dierence, it does not dene these terms and does not provide any list of these acts. Scholars do not provide much opinion in this matter either, leaving the issue for consideration by particular legislation and legal practice. However, the exact denition of dierences between the above-mentioned acts of admi- nistration is of great practical importance for the validity of acts related to the administration of ecclesiastical property. e article presented herein, based on an analysis of Can. 1277 and Can. 1281 §1, and §2 of CIC, indicates the existing dierences in terminology, and underlines the urgent need to develop a list of extraordinary acts of administration of ecclesiastical goods to ensure the stability of this kind of legal action, and draws attention to the criteria by which acts of extraordinary administration should be formulated. 

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