scholarly journals The development of diagnostics methodological principles of the railway rolling stock on the basis of the analysis of dynamic vibration processes of the rail

2018 ◽  
Vol 157 ◽  
pp. 03007 ◽  
Author(s):  
Juraj Gerlici ◽  
Olena Nozhenko ◽  
Ganna Cherniak ◽  
Mykola Gorbunov ◽  
Rostyslav Domin ◽  
...  
Keyword(s):  
Vertical Direction ◽  
Theoretical Research ◽  
Rolling Stock ◽  
Experimental Data Processing ◽  
Methodology Development ◽  
Additional Information ◽  
Dynamic Vibration ◽  
Train Speed ◽  
Methodological Principles ◽  
The Impact

The paper discusses the preconditions of the methodology development of diagnosis system for assessing dynamic impact of the rolling stock on the basis of processing and analysis of data obtained in operation on the results of measurement of parameters that characterize dynamic vibration processes of the mechanical system of “rolling stock – track”. On the basis of usage of the processing methods of time series and stochastic processes there has been established the relationship between these dynamic processes and wheel defects, and designed experimental data processing algorithms, which in the future will be an integral part of the intellectual systems of decision making when assessing the impact level of the rolling stock on the track. The article presents some results of the experimental and theoretical research of the rail accelerations data, which have been registered during passing of the train. The computational algorithm of the specialized pre-processing of the multidimensional signal recorded by this system is described. The advantage of this algorithm is that it does not require additional information about the train speed on the section equipped with the monitoring system, about the number of wheel pairs of locomotives and train cars, and about the distances between the wheel pairs. Based on the processing results of accelerations of the rails there have been set the parameters of increase in all statistical indicators with increase in the train speed. It is noted that the level of indicators for accelerations of the rails in the vertical direction is twice as high as the corresponding parameters in the horizontal direction.

Method for increasing the speed of an electrodynamic shaker for vibration test of rolling stock equipment

2021 ◽  
pp. 107754632110466
Author(s):  
Peng Wang ◽  
Hua Deng ◽  
Yue Liu ◽  
Yi-ming Wang ◽  
Yi Zhang ◽  
...  
Keyword(s):  
Input Impedance ◽  
Vertical Direction ◽  
Maximum Velocity ◽  
Rolling Stock ◽  
Vibration Test ◽  
Vibration Testing ◽  
High Frequencies ◽  
Electrodynamic Shaker ◽  
Long Life ◽  
The Impact

The velocity required in IEC 61373 for long-life random vibration testing of Category-3 rolling stock equipment in the vertical direction is 2.7821 m/s, but the maximum velocity of existing electrodynamic shakers falls in the range of 2–2.5 m/s. In this study, an electrodynamic shaker with a velocity satisfying the requirements for vibration testing of Category-3 rolling stock equipment was developed. First, mechanical and equivalent circuit models of an electrodynamic shaker were developed. On this basis, reducing the impedance of the armature coil was identified as the best option for increasing the velocity of the shaker. However, owing to the impact of the back electromotive force of the armature coil, a decrease in the input impedance of the armature coil at low frequencies leads to an increase in its input impedance at high frequencies. To reduce the input impedance at high frequencies, a shading coil was incorporated into the circuit. The shading coil-incorporated new design was modeled using equivalent circuits and simulated numerically. The results showed that the improvement measures—incorporating a shading coil, increasing the cross-sectional area, and reducing the number of turns of the armature coil—effectively reduced the input impedance of the armature coil, thereby increasing the armature coil current and the velocity of the shaker. Finally, a shaker with a maximum velocity of 3.2 m/s was fabricated based on the new design and was validated to satisfy the high-velocity requirement for the long-life vibration test of Category-3 equipment in the vertical direction as specified in IEC 61373.

Development of a stand for maintenance and repair of railway equipment units

2020 ◽  
Vol 1 (3) ◽  
pp. 210-215
Author(s):  
S. P. Lysy ◽  
I. A. Polikanova ◽  
M. A. Vishnikina
Keyword(s):  
Bending Strength ◽  
Classical Mechanics ◽  
Metal Structure ◽  
Theoretical Research ◽  
Practical Significance ◽  
Rolling Stock ◽  
Design Parameters ◽  
Experimental Data Processing ◽  
Maintenance And Repair ◽  
Critical Components

The development of a stand for maintenance and repair of railway equipment units includes theoretical and practical research. Theoretical research is the basis for obtaining practical results. Special attention is paid to the calculations of critical components and parts. By means of the stand, cars, locomotives, electric locomotives and other rolling stock can be brought into working condition. The purpose of the work is to develop a stand for maintenance and repair of railway equipment units. The object of the study is the technological process of the stand for the maintenance and repair of railway equipment units. The scientific novelty of the work is: theoretical justification of the stand design parameters; design and technological scheme of the stand; optimal design and operating parameters of the stand; estimated performance indicators of the stand. The practical significance lies in the use of the stand on the repair sections of the railway, reducing the labor intensity of the work performed, ease of maintenance, and the lowest cost of manufacturing. Theoretical methods were based on the principles of classical mechanics, mathematical analysis, synthesis, modeling, etc. Experimental data processing was performed using the application programs “Compass-3D”, Statistica 6.0, MathCAD. Calculations of the metal structure for bending strength, welded joints, and bed clamps were performed. The calculation of the bending strength of the metal structure was performed and the maximum stresses were found to be within the permissible limits. The condition for the strength of the welded joint is met. The calculation of the bed clips showed that the condition of wear resistance is met.

scholarly journals A Novel Profiler Driven by Tidal Energy for Long Term Oceanographic Measurements in Offshore Areas

2021 ◽  
Vol 9 (5) ◽  
pp. 534
Author(s):  
Xiaoya Zang ◽  
Zhujun Zhang ◽  
Wei Fan
Keyword(s):  
Theoretical Model ◽  
Current Velocity ◽  
Electric Energy ◽  
Vertical Direction ◽  
Tidal Energy ◽  
Theoretical Research ◽  
Hydrodynamic Characteristics ◽  
The Cross ◽  
The Impact

In this paper, an innovative profiler driven by tidal energy for long-term oceanographic measurements in offshore areas with abundant tidal resources is investigated. The profiler is mainly composed of an oceanographic data collection system equipped with various sensors and a cross-plate that can make an upward or downward movement under the impact of tidal currents. Theoretical research is carried out through static analysis and numerical simulation, mainly studying the hydrodynamic characteristics of the cross-plate and its dynamic response to the current velocity. The theoretical model is verified by comparison with experiments. The research results show that tidal energy can be used as a kind of energy to drive the profiler’s ascent and descent motion and to continuously measure ocean parameters without using electric energy. The theoretical model established in this study can roughly predict the position of the profiler observation platform in the vertical direction under various current velocities. Furthermore, by studying the relationship between the current velocities and the lift and drag forces of the cross-plate in the fluid, it is recognized that the current velocity is an important factor affecting the stability of the system’s motion. It is hoped that this research will contribute to the development of profilers.

INNOVATIVE ARCHITECTURAL IDEAS OF THE FUTURE DWELLINGS

2020 ◽  
Vol 2 (2) ◽  
pp. 67-75
Author(s):  
Dzhyhil Yu. ◽  
Keyword(s):  
Personal Responsibility ◽  
Traffic Noise ◽  
Modern World ◽  
Future Research ◽  
Housing Design ◽  
Residential Architecture ◽  
Planning Decisions ◽  
National University ◽  
Methodological Principles ◽  
The Impact

Residential architecture has one of the most conservative styles based on its specifics. However, today this type of architecture seeks to actively respond to changes in the modern world. These changes are caused by multiple factors, among them are: technological and information progress; lack of resources and environmental pollution; military conflicts and population migration etc. The purpose of this article is to summarize the experience of the Department of Architectural Environment of Lviv Polytechnic National University over housing issues and outline the methodological principles of innovation in designing both individual houses and the architectural environment of residential formations. While writing this article, we analyzed the 15-year experience of Architectural Environment's Department diploma projects. The unique feature of these projects is the priority on the design of the environment. The evolution of diploma project topics is revealed on multiple distinctive examples such as the reconstruction of old buildings in Lviv and the construction of prefabricated homes and container-type housing. Futuristic settlements are represented in projects such as “The Ocean Settlements” and “Prykarpatsk - the City of Future”. Research projects were developed to study current trends in housing design and the impact of innovative technologies on planning decisions. These projects discoursed the protection of housing from traffic noise and issues related to environmental preservation. Innovative architectural ideas of future housing, developed by students in these projects, are based on a combination of aesthetic, technical, and social components of architecture. The conclusion indicates that when educating future architects, it is important to teach them the basics of the craft, as well as the ability to defend their innovative ideas. The emphasis is placed on the importance of educating the architect's personal responsibility for their own design solutions. It is stated that professional motivation and the ability to constantly renew previously acquired knowledge and skills will be among the main tasks in training future architects.

The impact of the new media on public relations in the public administration in Kurdistan Region

2019 ◽  
Vol 7 (1) ◽  
pp. 268-288
Author(s):  
Dlan Ismail Mawlud ◽  
Hoshyar Mozafar Ali
Keyword(s):  
Information Technology ◽  
New Media ◽  
Public Relations ◽  
Public Administration ◽  
Management System ◽  
Theoretical Research ◽  
Kurdistan Region ◽  
The Public ◽  
Government Institutions ◽  
The Impact

The development of technology, information technology and various means of communication have a significant impact on public relations activity; especially in government institutions. Many government institutions have invested these means in their management system, in order to facilitate the goals of the institution, and ultimately the interaction between the internal and external public. In this theoretical research, I tried to explain the impact of the new media on public relations in the public administration, based on the views of specialists. The aim of the research is to know the use of the new media of public relations and how in the system of public administration, as well as, Explaining the role it plays in public relations activities of government institutions. Add to this, analyzing the way of how new media and public relations participate in the birth of e-government. In the results, it is clear that the new media has facilitated public relations between the public and other institutions, as it strengthened relations between them

scholarly journals Improving Drought Tolerance in Mungbean (Vigna radiata L. Wilczek): Morpho-Physiological, Biochemical and Molecular Perspectives

Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1534
Author(s):  
Chandra Mohan Singh ◽  
Poornima Singh ◽  
Chandrakant Tiwari ◽  
Shalini Purwar ◽  
Mukul Kumar ◽  
...  
Keyword(s):  
Drought Stress ◽  
Drought Tolerance ◽  
Crop Production ◽  
Mitigation Strategies ◽  
Theoretical Research ◽  
Whole Genome Sequence ◽  
Complex Nature ◽  
Drought Tolerant ◽  
Breeding Programmes ◽  
The Impact

Drought stress is considered a severe threat to crop production. It adversely affects the morpho-physiological, biochemical and molecular functions of the plants, especially in short duration crops like mungbean. In the past few decades, significant progress has been made towards enhancing climate resilience in legumes through classical and next-generation breeding coupled with omics approaches. Various defence mechanisms have been reported as key players in crop adaptation to drought stress. Many researchers have identified potential donors, QTLs/genes and candidate genes associated to drought tolerance-related traits. However, cloning and exploitation of these loci/gene(s) in breeding programmes are still limited. To bridge the gap between theoretical research and practical breeding, we need to reveal the omics-assisted genetic variations associated with drought tolerance in mungbean to tackle this stress. Furthermore, the use of wild relatives in breeding programmes for drought tolerance is also limited and needs to be focused. Even after six years of decoding the whole genome sequence of mungbean, the genome-wide characterization and expression of various gene families and transcriptional factors are still lacking. Due to the complex nature of drought tolerance, it also requires integrating high throughput multi-omics approaches to increase breeding efficiency and genomic selection for rapid genetic gains to develop drought-tolerant mungbean cultivars. This review highlights the impact of drought stress on mungbean and mitigation strategies for breeding high-yielding drought-tolerant mungbean varieties through classical and modern omics technologies.

News and Idiosyncratic Volatility: The Public Information Processing Hypothesis*

2020 ◽  
Author(s):  
Robert F Engle ◽  
Martin Klint Hansen ◽  
Ahmet K Karagozoglu ◽  
Asger Lunde
Keyword(s):  
Information Processing ◽  
Public Information ◽  
Selection Procedure ◽  
Autoregressive Process ◽  
Return Volatility ◽  
Market Outcomes ◽  
The Public ◽  
Additional Information ◽  
Financial News ◽  
The Impact

Abstract Motivated by the recent availability of extensive electronic news databases and advent of new empirical methods, there has been renewed interest in investigating the impact of financial news on market outcomes for individual stocks. We develop the information processing hypothesis of return volatility to investigate the relation between firm-specific news and volatility. We propose a novel dynamic econometric specification and test it using time series regressions employing a machine learning model selection procedure. Our empirical results are based on a comprehensive dataset comprised of more than 3 million news items for a sample of 28 large U.S. companies. Our proposed econometric specification for firm-specific return volatility is a simple mixture model with two components: public information and private processing of public information. The public information processing component is defined by the contemporaneous relation with public information and volatility, while the private processing of public information component is specified as a general autoregressive process corresponding to the sequential price discovery mechanism of investors as additional information, previously not publicly available, is generated and incorporated into prices. Our results show that changes in return volatility are related to public information arrival and that including indicators of public information arrival explains on average 26% (9–65%) of changes in firm-specific return volatility.

scholarly journals Grading Investment Diversification Options in Presence of Non-Historical Financial Information

Mathematics ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 692
Author(s):  
Clara Calvo ◽  
Carlos Ivorra ◽  
Vicente Liern ◽  
Blanca Pérez-Gladish
Keyword(s):  
Risk Measure ◽  
Statistical Information ◽  
Expected Returns ◽  
Financial Assets ◽  
Expected Return ◽  
Additional Information ◽  
Subjective Risk ◽  
The Impact ◽  
Statistical Risk ◽  
Reduction Index

Modern portfolio theory deals with the problem of selecting a portfolio of financial assets such that the expected return is maximized for a given level of risk. The forecast of the expected individual assets’ returns and risk is usually based on their historical returns. In this work, we consider a situation in which the investor has non-historical additional information that is used for the forecast of the expected returns. This implies that there is no obvious statistical risk measure any more, and it poses the problem of selecting an adequate set of diversification constraints to mitigate the risk of the selected portfolio without losing the value of the non-statistical information owned by the investor. To address this problem, we introduce an indicator, the historical reduction index, measuring the expected reduction of the expected return due to a given set of diversification constraints. We show that it can be used to grade the impact of each possible set of diversification constraints. Hence, the investor can choose from this gradation, the set better fitting his subjective risk-aversion level.

scholarly journals A next step in disruption management: combining operations research and complexity science

2021 ◽  
Author(s):  
Mark M. Dekker ◽  
Rolf N. van Lieshout ◽  
Robin C. Ball ◽  
Paul C. Bouman ◽  
Stefan C. Dekker ◽  
...  
Keyword(s):  
Operations Research ◽  
Complexity Science ◽  
Rolling Stock ◽  
Accurate Information ◽  
Disruption Management ◽  
Railway Systems ◽  
Decentralized Decision Making ◽  
Control Situations ◽  
Management Techniques ◽  
The Impact

AbstractRailway systems occasionally get into a state of being out-of-control, meaning that barely any train is running, even though the required resources (infrastructure, rolling stock and crew) are available. Because of the large number of affected resources and the absence of detailed, timely and accurate information, currently existing disruption management techniques cannot be applied in out-of-control situations. Most of the contemporary approaches assume that there is only one single disruption with a known duration, that all information about the resources is available, and that all stakeholders in the operations act as expected. Another limitation is the lack of knowledge about why and how disruptions accumulate and whether this process can be predicted. To tackle these problems, we develop a multidisciplinary framework combining techniques from complexity science and operations research, aiming at reducing the impact of these situations and—if possible—avoiding them. The key elements of this framework are (i) the generation of early warning signals for out-of-control situations, (ii) isolating a specific region such that delay stops propagating, and (iii) the application of decentralized decision making, more suited for information-sparse out-of-control situations.

scholarly journals Identification of Sleeper Support Conditions Using Mechanical Model Supported Data-Driven Approach

Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3609
Author(s):  
Mykola Sysyn ◽  
Michal Przybylowicz ◽  
Olga Nabochenko ◽  
Lei Kou
Keyword(s):  
High Speed ◽  
Experimental Studies ◽  
Dynamic Interaction ◽  
Theoretical Research ◽  
Rolling Stock ◽  
Monitoring Methods ◽  
Beam Dynamic ◽  
Track Geometry ◽  
Data Driven Approach ◽  
Support Conditions

The ballasted track superstructure is characterized by a relative quick deterioration of track geometry due to ballast settlements and the accumulation of sleeper voids. The track zones with the sleeper voids differ from the geometrical irregularities with increased dynamic loading, high vibration, and unfavorable ballast-bed and sleeper contact conditions. This causes the accelerated growth of the inhomogeneous settlements, resulting in maintenance-expensive local instabilities that influence transportation reliability and availability. The recent identification and evaluation of the sleeper support conditions using track-side and on-board monitoring methods can help planning prevention activities to avoid or delay the development of local instabilities such as ballast breakdown, white spots, subgrade defects, etc. The paper presents theoretical and experimental studies that are directed at the development of the methods for sleeper support identification. The distinctive features of the dynamic behavior in the void zone compared to the equivalent geometrical irregularity are identified by numeric simulation using a three-beam dynamic model, taking into account superstructure and rolling stock dynamic interaction. The spectral features in time domain in scalograms and scattergrams are analyzed. Additionally, the theoretical research enabled to determine the similarities and differences of the dynamic interaction from the viewpoint of track-side and on-board measurements. The method of experimental investigation is presented by multipoint track-side measurements of rail-dynamic displacements using high-speed video records and digital imaging correlation (DIC) methods. The method is used to collect the statistical information from different-extent voided zones and the corresponding reference zones without voids. The applied machine learning methods enable the exact recent void identification using the wavelet scattering feature extraction from track-side measurements. A case study of the method application for an on-board measurement shows the moderate results of the recent void identification as well as the potential ways of its improvement.

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