scholarly journals Methods and instruments for stray current verification in DC rapid transit and railway systems

Author(s):  
Andrea Mariscotti

Modern electrified transportation systems feature increasing installed power and performance and correspondingly stray current phenomena and corrosion are receiving more attention in terms of contractual specifications and request of final validation of proposed solutions, as well as a maintenance program that can actively tackle stray current issues. The problem is complex for the system physical extension, difficult measurement conditions and variability of electrical parameters. This work considers validation of stray current protection performance, in terms of track voltage, track leakage and collected current, and impressed potential on structures along the right-ofway. The exemplification of the specifications of a hypothetical instrument and setup support the discussion.

Sensors ◽  
2020 ◽  
Vol 20 (22) ◽  
pp. 6610
Author(s):  
Andrea Mariscotti

Electrified transportation systems (ETSs) are affected by stray current problems impacting within and outside the right of way on reinforcement, buried metal structures and foundations. Stray current protection systems have recently been integrated in the track structure. Track electrical quantities are, thus, usually measured to assess track insulation and protection efficiency but should be backed up by additional measurements at the affected structures and installations, in order to assess their exposure and risk of corrosion. Ideally, a stray current monitoring system proceeds from the measurement of these quantities, to data collection and archival, to data presentation, analysis and prediction. Feasible sensors and probes, the impact of environmental conditions and uncertainty are considered for the measurement at the physical level. Data analysis is critically reviewed considering the variability of operating conditions and the effectiveness of each quantity as indicator of track insulation and protection efficiency. Given the normal spread of values, for data presentation and interpretation, suitable techniques are considered based on averaging, curve similarity and feature extraction, and also for the task of assessing compliance to limits or reference values and establishing a trend that may drive informed maintenance decision.


2021 ◽  
Vol 13 (16) ◽  
pp. 8706
Author(s):  
Nir Sharav ◽  
Yoram Shiftan

We present a new urban transit investment model, integrating transport economic theory regarding optimal investment with transport modeling, planning, and network design. The model expands on the theory of optimal transit network planning and investment, accounting for the effects of the investment on accessibility, level of service, and speed. The model seeks long-term optimal transit investment and optimal road pricing simultaneously in an integrated, unified model. To illustrate the advantages of our approach, we applied our empirical model to two case studies, Tel Aviv and Toronto, integrating our theoretical contribution into practice. Our results demonstrate the model’s ability to indicate the optimal transit mode and investment on a corridor level and the total investment required for the city transit network. The model results were compared to the actual and planned transit networks of Tel Aviv and Toronto and showed the model’s capability to produce a good balance of strategic design and network details. The research concludes that applying the right toll with the applicable transit investment is crucial for obtaining an efficient network and performance. This research can direct planners and policymakers in planning urban transport and provide a comprehensive set of guidelines for optimizing the simultaneous investment in mass transit and the congestion toll toward more sustainable cities and transportation systems.


2020 ◽  
Vol 10 (1) ◽  
pp. 63-71
Author(s):  
Nurhaeda Abbas ◽  
Anggraini Sukmawati ◽  
Muhammad Syamsun

Today the performance measurement of Muhammadiyah Luwuk uUniversity’s performance has not formulated yet based on University’s vision and mission. It will affect the strategic steps needed and performance improvement efforts in the future.  Human resource scorecard is the right system to be applied in Muhammadiyah Luwuk University. The purpose of this study is to designed a performance measurement system at Muhammadiyah Luwuk University using the Human Resource Scorecard with four perspectives: stakeholder, academic management and kemuhammadiyaan, operational and innovation, as well as and learning. Data was analyzed by analytical hierarchy process method. This research was conducted by distributing questionnaires, focus group discussions and in-depth interview with stakeholders at Muhammadiyah Luwuk University. The results showed that there were 14 strategic objectives and 33 key performance indicators to be achieved by the priority objectives, which are: empowerment and development of faculty, increased administrative process quality, improved sound budget performance and, improvement of the relationship with stakeholders.


Author(s):  
Emanuela Gualdi-Russo ◽  
Natascia Rinaldo ◽  
Alba Pasini ◽  
Luciana Zaccagni

The aims of this study were to develop and validate an instrument to quantitatively assess the handedness of basketballers in basketball tasks (Basketball Handedness Inventory, BaHI) and to compare it with their handedness in daily activities by the Edinburgh Handedness Inventory (EHI). The participants were 111 basketballers and 40 controls. All subjects completed the EHI and only basketballers filled in the BaHI. To validate the BaHI, a voluntary subsample of basketballers repeated the BaHI. Exploratory and confirmatory factor analyses supported a two-factor model. Our results show that: (i) Handedness score (R) in daily actions did not differ between basketball players (R by EHI = 69.3 ± 44.6) and the control group (R by EHI = 64.5 ± 58.6); (ii) basketballers more frequently favored performing certain sport tasks with the left hand or mixed hands (as highlighted by R by BaHI = 50.1 ± 47.1), although their choice was primarily the right hand in everyday gestures; and (iii) this preference was especially true for athletes at the highest levels of performance (R by BaHI of A1 league = 38.6 ± 58.3) and for those playing in selected roles (point guard’s R = 29.4 ± 67.4). Our findings suggest that professional training induces handedness changes in basketball tasks. The BaHI provides a valid and reliable measure of the skilled hand in basketball. This will allow coaches to assess mastery of the ball according to the hand used by the athlete in the different tasks and roles.


2021 ◽  
Vol 11 (3) ◽  
pp. 376
Author(s):  
Carmelo Mario Vicario ◽  
Gabriella Martino ◽  
Alex Marcuzzo ◽  
Giuseppe Craparo

Neuroscience research links alexithymia, the difficulty in identifying and describing feelings and emotions, with left hemisphere dominance and/or right hemisphere deficit. To provide behavioral evidence for this neuroscientific hypothesis, we explored the relationship between alexithymia and performance in a line bisection task, a standard method for evaluating visuospatial processing in relation to right hemisphere functioning. We enrolled 222 healthy participants who completed a version of the 20-item Toronto Alexithymia Scale (TAS-20), which measures alexithymia, and were asked to mark (bisect) the center of a 10-cm horizontal segment. The results document a significant rightward shift in the center of the line in participants with borderline and manifest alexithymia compared with non-alexithymic individuals. The higher the TAS-20 score, the greater the rightward shift in the line bisection task. This finding supports the right hemisphere deficit hypothesis in alexithymia and suggests that visuospatial abnormalities may be an important component of this mental condition.


2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
R. Mazón-Hernández ◽  
J. R. García-Cascales ◽  
F. Vera-García ◽  
A. S. Káiser ◽  
B. Zamora

The main priority in photovoltaic (PV) panels is the production of electricity. The transformation of solar energy into electricity depends on the operating temperature in such a way that the performance increases with the decreasing temperatures. In the existing literature, different cooling techniques can be found. The purpose of most of them is to use air or water as thermal energy carriers. This work is focused on the use of air as a working fluid whose movement is either induced by natural convection or forced by means of a fan. The aim of this study is to characterise the electrical behaviour of the solar panels in order to improve the design of photovoltaic installations placed in roof applications ensuring low operating temperatures which will correct and reverse the effects produced on efficiency by high temperature. To do this, a test installation has been constructed at the Universidad Politécnica de Cartagena in Spain. In this paper, the results of the tests carried out on two identical solar panels are included. One of them has been modified and mounted on different channels through which air flows. The different studies conducted show the effects of the air channel cross-section, the air velocity, and the panel temperature on the electrical parameters of the solar panels, such as the voltage, current, power, and performance. The results conclude that the air space between the photovoltaic panels and a steel roof must be high enough to allow the panel to be cooled and consequently to achieve higher efficiency.


Author(s):  
Jan-jaap Moerman ◽  
Jan Maarten Schraagen ◽  
Jan Braaksma ◽  
Leo van Dongen

AbstractGraceful extensibility has been recently introduced and can be defined as the ability of a system to extend its capacity to adapt when surprise events challenge its boundaries. It provides basic rules that govern adaptive systems. Railway transportation systems can be considered cyber-physical systems that comprise interacting digital, analog, physical, and human components engineered for safe and reliable railway transport. This enables autonomous driving, new functionalities to achieve higher capacity, greater safety, and real-time health monitoring. New rolling stock introductions require continuous adaptations to meet the challenges of these complex railway systems as an introduction takes several years to complete and deals with changing stakeholder demands, new technologies, and technical constraints which cannot be fully predicted in advance. To sustain adaptability when introducing new rolling stock, the theory of graceful extensibility might be valuable but needs further empirical testing to be useful in the field. This study contributes by assessing the proto-theorems of graceful extensibility in a case study in the railway industry by means of adopting pattern-matching analysis. The results of this study indicate that the majority of theoretical patterns postulated by the theory are corroborated by the data. Guidelines are proposed for further operationalization of the theory in the field. Furthermore, case results indicate the need to adopt management approaches that accept indeterminism as a complement to the prevailing deterministic perspective, to sustain adaptability and deal effectively with surprise events. As such, this study may serve other critical asset introductions dealing with cyber-physical systems in their push for sustained adaptability.


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