scholarly journals EXTRATEGIAS DE MEJORA DE LÍNEAS FERROVIARIAS

Author(s):  
José Daniel Costa Seijas ◽  
José Manuel Cubela

The main objectives of investment on railway are improving connectivity and access to services; generate employment and amenities; while delivering cuts in carbon emissions, reductions in traffic noise, pollution and congestion. Within that general context, the existing options to improve a railway line are the upgrading of the existing line, which is called the brown field option, or to build a brand new line in the corridor, which is called the green field option and which is assumed a state of art line, i.e. a High Speed Line. There is, nevertheless, a third option that could be followed in which, first the existing line is upgraded and then a new High Speed Line is built in the same corridor. This latter option is acknowledged as economically inefficient, but it is needed to find out to what extend that assertion is true. The purpose of this study is, then, to reach a conclusion on that statement through the analyses of actual cases, i.e. not through a theoretical exercise but through an empirical research. In the first stage of the research two corridors that met the requirements of the study were identified: the Madrid - Valencia Line in Spain and Bordeaux – Spain Line in France. From the analysis of those corridors it was learnt that, indeed, building a new High Speed Line after upgrading the existing line in that corridor will not be economically efficient unless the new line is built after a number of years. That delay could be around 10 years, and will depend on the level of investment carried out for the upgrading and the expected growth of transport demand in the corridor.DOI: http://dx.doi.org/10.4995/CIT2016.2016.4081 

2013 ◽  
Vol 40 (2) ◽  
Author(s):  
Ni Ketut Susilawati ◽  
Wayan Sudana ◽  
Eka Putra Setiawan

Background: Noise pollution or noise is an unwanted sound which is disturbing to human beings.However small or soft the sound, if it is undesirable it is considered as noise. Noise induced hearingloss is a sensorineural hearing loss that is commonly encountered second to presbycusis. Purpose: Toknow the effect of traffic noise exposure on hearing impairment to the employees of the Parking DistrictCompany of the Denpasar city and to improve diagnostic detection on hearing impairment caused bynoise. Method: A cross sectional study was conducted at the Parking District Company office. Thepopulations of this study were the employees of the Parking District Company. Samples of this study were the employees who were exposed to traffic noise and control samples were an employee who was unexposed. Samples were selected by simple random sampling. Results: From 40 parking attendants,27 persons (67.5%) aged above 35 years old. The parking attendants who had been working for ten to fifteen years were 36 persons (90%) and no history using ear protection when working. Seven persons(17.5%) had referred DPOAE upon examination with increase hearing threshold on audiogram result.In this study the parking attendants who had hearing deficit induced by noise were 7 persons (17.5%)and only one person (2.5%) in control group. There was a statistically significant effect of traffic noiseto hearing function deficit (p<0.05). Conclusion: Traffic noise has effect in hearing function deficit onthe parking attendants.ORLI Vol. 40 No. 2 Tahun 2010Key words: NIHL, parking attendant, audiometry, DPOAE.


2021 ◽  
Vol 7 (20) ◽  
pp. eabe2405
Author(s):  
Henrik Brumm ◽  
Wolfgang Goymann ◽  
Sébastien Derégnaucourt ◽  
Nicole Geberzahn ◽  
Sue Anne Zollinger

Noise pollution has been linked to learning and language deficits in children, but the causal mechanisms connecting noise to cognitive deficiencies remain unclear because experimental models are lacking. Here, we investigated the effects of noise on birdsong learning, the primary animal model for vocal learning and speech development in humans. We found that traffic noise exposure retarded vocal development and led to learning inaccuracies. In addition, noise suppressed immune function during the sensitive learning period, indicating that it is a potent stressor for birds, which is likely to compromise their cognitive functions. Our results provide important insights into the consequences of noise pollution and pave the way for future studies using birdsong as an experimental model for the investigation of noise-induced learning impairments.


Author(s):  
Xuewu Zhang ◽  
Yansheng Gong ◽  
Chen Qiao ◽  
Wenfeng Jing

AbstractThis article mainly focuses on the most common types of high-speed railways malfunctions in overhead contact systems, namely, unstressed droppers, foreign-body invasions, and pole number-plate malfunctions, to establish a deep-network detection model. By fusing the feature maps of the shallow and deep layers in the pretraining network, global and local features of the malfunction area are combined to enhance the network's ability of identifying small objects. Further, in order to share the fully connected layers of the pretraining network and reduce the complexity of the model, Tucker tensor decomposition is used to extract features from the fused-feature map. The operation greatly reduces training time. Through the detection of images collected on the Lanxin railway line, experiments result show that the proposed multiview Faster R-CNN based on tensor decomposition had lower miss probability and higher detection accuracy for the three types faults. Compared with object-detection methods YOLOv3, SSD, and the original Faster R-CNN, the average miss probability of the improved Faster R-CNN model in this paper is decreased by 37.83%, 51.27%, and 43.79%, respectively, and average detection accuracy is increased by 3.6%, 9.75%, and 5.9%, respectively.


2006 ◽  
Vol 123 (1-3) ◽  
pp. 413-430 ◽  
Author(s):  
Guoxia Ma ◽  
Yujun Tian ◽  
Tianzhen Ju ◽  
Zhengwu Ren

2008 ◽  
Vol 18 (04) ◽  
pp. 913-922 ◽  
Author(s):  
SIDDHARTH RAJAN ◽  
UMESH K. MISHRA ◽  
TOMÁS PALACIOS

This paper provides an overview of recent work and future directions in Gallium Nitride transistor research. We discuss the present status of Ga -polar AlGaN / GaN HEMTs and the innovations that have led to record RF power performance. We describe the development of N -polar AlGaN / GaN HEMTs with microwave power performance comparable with state-of-art Ga -polar AlGaN / GaN HEMTs. Finally we will discuss how GaN -based field effect transistors could be promising for a less obvious application: low-power high-speed digital circuits.


2006 ◽  
Vol 120 (1-3) ◽  
pp. 499-525 ◽  
Author(s):  
Ahmad Jamrah ◽  
Abbas Al-Omari ◽  
Reem Sharabi

Noise Mapping ◽  
2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Miguel Arana ◽  
Ricardo San Martin ◽  
Juan C. Salinas

AbstractTwo of the main objectives of the European Directive on environmental noise are, firstly, to unify acoustic indices for assessing environmental noise and, secondly, to standardize assessment methodologies. The ultimate goal is to objectively and comparably manage the impact and evolution of environmental noise caused both by urban agglomerations and by traffic infrastructures (roads, rails and airports). The use of common indices and methodologies (together with five-year plan assessment required by the authorities in charge) should show how noise pollution levels are evolving plus the effectiveness of corrective measures implemented in the action plans. In this paper, available results fromnumerous European agglomerations (with particular emphasis on Spanish agglomerations) are compared and analysed. The impact and its evolution are based on the percentage of people exposed to noise. More specifically, it demonstrates the impact caused by road traffic, which proves to be the main noise source in all agglomerations. In many cases, the results are extremely remarkable. In some case, the results are illogical. For such cases, it can be concluded that either assessment methodologies have been signifi- cantly amended or the input variables to the calculation programs have been remarkably changed. The uncertainty associated with the results is such that, in our opinion, no conclusions can be drawn concerning the effectiveness of remedial measures designed within the action plans after the Directive’s first implementation Phase.


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