Current Issue : April - June Volume : 2016 Issue Number : 2 Articles : 6 Articles
Hybrid III six-year-old (6YO) child dummy head model was developed and validated for frontal impact assessment according to\nthe specifications contained in Code of Federal Regulations, Title 49, Part 572.122, Subpart N by Livermore Software Technology\nCorporation (LSTC). This work is aimed at improving biofidelity of the head for frontal impact and also extending its application to\nlateral impact assessment bymodifying the head skin viscoelastic properties and validating the head response using the scaled nineyear-\nold (9YO) child cadaver head response recently published in the literature. The modified head model was validated for two\ndrop heights for frontal, right, and left parietal impact locations. Peak resultant acceleration of the modified head model appeared\nto have good correlation with scaled 9YO child cadaver head response for frontal impact on dropping from 302mm height and\nfair correlation with 12.3% difference for 151mm drop height. Right parietal peak resultant acceleration values correlate well with\nscaled 9YO head experimental data for 153mm drop height, while fair correlation with 16.4% difference was noticed for 302mm\ndrop height. Left parietal, however, shows low biofidelity for the two drop heights as the difference in head acceleration response\nwas within 30%. The modified head model could therefore be used to estimate injuries in vehicle crash for head parietal impact\nlocations which cannot be measured by the current hybrid III dummy head model....
Introduction Car-to-X Communications are envisioned to improve\nroad safety, traffic efficiency, and information services\nthrough short-range and real-time systems. The enabling applications\nhave varied requirements such as low latency, specific\nforwarding patterns, and reliable data exchange between\nvehicles and infrastructure. Hence, a cross-layer architecture\nfor vehicular applications should be defined according to the\ngoals of the implementation, so as to consider proper routing\nand dissemination mechanisms, communication protocols,\nand the application�s design and operation.\nMethods In this context, we propose the characterization of\nthe upper layers of a safety-oriented Car-to-Car application.\nWe propose a cross-layer application/network layer design for\na Post Collision Notification (PCN) application, and by means\nof a coupled simulation model that combines the\ncommunication network with vehicular traffic flow, we assess\nthe performance of the application design.\nResults Three main results can be derived from our work.\nFirst, the selected geocast protocol (DRG) shows to be an\naccurate protocol for safety applications and it may be a scalable\nrouting mechanism for other applications. Second, that\nDRG is effective even for larger urban areas. And third, there\nis a reduction of acceleration and speed of the closest vehicles\nto the incident zone, which is a positive impact of the PCN\napplication on the traffic flow.\nConclusions Consequently, the proposed cross-layer architecture\nand the implementation of geocast routing has shown a suitable\nsupport and good performance for safety applications, and could\nbe extended to other application on the Car-to-X domain....
Left-turning traffic without a protected left-turn signal is one of the major safety concerns at urban\nintersections. Though an average of only l0% - 15% of all approaching traffic turns left, significantly\na large proportion of left-turn crashes occur involving 21% of all intersection fatal crashes. Where\ntraditional safety countermeasures of signal timing-phasing and use of flashing yellow light have\nreportedly failed to significantly reduce the rate of crashes, an in-vehicle advance collision warning\nmessage can be helpful to reduce left-turn collisions at intersections. In this study, an in-vehicle\naudio warning application has been designed by providing two safety warning messages (Advance\nWarning Message and Safe Left-turn Maneuver Message) under the vehicle to vehicle (V2V)\ncommunication system, which is triggered based on the acceptable gaps of oncoming opposing vehicles\nfor a safe left-turn. A driving simulator test has been conducted with 30 participants to investigate\nthe impacts of warning messages on performance measures such as speed and acceleration\nprofiles, collision records, brake reaction distance, and intersection clearance time. Statistical\nresults showed that with the help of these messages, all participants were able to reduce speeds\nand accelerations and chose suitable gaps without potential conflicts. Moreover, the results of questionnaire\nanalysis provide a positive acceptability especially for the Safe Left-turn Maneuver Message.\nBased on the performance measurements, this type of safety warning messages can be recommended\nfor possible real-road tests for practical applications....
Poor cruise performance of Electric Vehicles (EVs) continues to be the primary reason that impends their market penetration.\nAdding more battery to extend the cruise range is not a viable solution as it increases the structural weight and capital cost of the\nEV. Simulations identified that a vehicle spends on average 15% of its total time in braking, signifying an immense potential of the\nutilization of regenerative braking mechanism. Based on the analysis, a 3kWauxiliary electrical unit coupled with the traction drive\nduring braking events increases the recoverable energy by 8.4%. In addition, the simulation revealed that, on average, the energy\ndrawn from the battery is reduced by 3.2% when traction drive is integrated with the air-conditioning compressor (an auxiliary\nelectrical load). A practical design solution of the integrated unit is also included in the paper. Based on the findings, it is evident\nthat the integration of an auxiliary unit with the traction drive results in enhancing the energy capturing capacity of the regenerative\nbraking mechanism and decreases the power consumed from the battery. Further, the integrated unit boosts other advantages such\nas reduced material cost, improved reliability, and a compact and lightweight design....
Nowadays, train control in-lab simulation tools play a crucial role in reducing extensive and expensive on-site railway testing\nactivities. In this paper, we present our contribution in this arena by detailing the internals of our European Railway Train\nManagement System in-lab demonstrator. This demonstrator is built over a general-purpose simulation framework, Riverbed\nModeler, previously Opnet Modeler. Our framework models both ERTMS subsystems, the Automatic Train Protection application\nlayer based on movement authority message exchange and the telecommunication subsystem based on GSM-R communication\ntechnology. We provide detailed information on our modelling strategy. We also validate our simulation framework with real\ntrace data. To conclude, under current industry migration scenario from GSM-R legacy obsolescence to IP-based heterogeneous\ntechnologies, our simulation framework represents a singular tool to railway operators. As an example, we present the assessment\nof related performance indicators for a specific railway network using a candidate replacement technology, LTE, versus current\nlegacy technology. To the best of our knowledge, there is no similar initiative able to measure the impact of the telecommunication\nsubsystem in the railway network availability....
There is a growing interest in understanding wave behavior in urban and suburban environment for 5th generation broadband\napplications.With the advent of using broadband technologies in buildings, office space and vehicle have become a necessity on a\nlarge scale.Models, predictions, and calculations for in-building, within a vehicle or near a reflective object with microscale details,\nare becoming highly classified in a competitive telecom environment. This paper provides an improved understanding of signal\nstrength behavior within suburban residences with predictions prequalified using a vehicular scanner. Supporting predictions are\nprovided by a ray tracing algorithm developed for dissertation. Results indicate signal strength variation of more than 50 dB from\nââ?¬Å?strong signalââ?¬Â locations such as room centers and far corners to ââ?¬Å?weak signalââ?¬Â locations where shadowing and tunneling effects\nare evident. Based on this unique classification a scheme is proposed which indicates that specular scattering provides the major\nsignal energy at more than 70% of the locations within the residences. Finally, an observed rake stabilizing effect is attributed to the\nproximity of strong scatterers....
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