Abstract

In any railway power supply system, the contact line is considered one of the most important component influencing the life cycle of the system. The analyses, which estimates the wearing of the contact line but also of the pantograph contact strips, are based on the value of the contact force, which defines the interaction between pantograph, as external component, and overhead contact line. The instrumentation solutions, developed in time of the same project, provide two systems focused for acquisitioning the acceleration and displacement information of the overhead contact line."br" The first developed system uses sensor devices hanging by the contact line, having as objective to collect acceleration information at the contact point of the moving pantograph; the system is described in this paper."br" The second developed system uses one high speed video camera, placed aside the rail track, which register the movements of the contact line. Being a very different technology this system will make subject of other article."br" The both systems have main focus to determine, indirectly, the value of the contact force, but also to optimise a list of controllable factors.

Abstract

Traffic accidents depend on many factors and circumstances. Important data are registered by taking photos of the accident place, measuring the deformations of vehicles and skidding and sliding traces. Weather conditions, drivers’ and pedestrian's actions are also taken into account. However the existing data are far from sufficient to conduct a research into traffic accidents. In such cases mathematical modelling and the application of computer programs are very helpful. This article deals with the processes during the collision of vehicles as well as the occupant's dynamics inside the vehicle. The research studies on what the occupant motion depends and what is the power balance between the occupant and safety means. The article offers a way of evaluating injuries, measuring the occupants’ acceleration and velocity, taking into account different distances inside the vehicle during an accident. First Published Online: 27 Oct 2010 Document type: Article

Abstract

In the present paper a method of analytical determination of reactions and angles of pressure is considered with the four-bar linkage as an example. The determined sequence for the expression of acceleration of the points and angle acceleration of the links is presented. Further the power analysis for Assur’s group is made. The equations of normal components of reactions are expressed as straight lines passing across given point in the given direction. The equations of the full reactions in the hinges are expressed as straight lines passing across two given points. After that the angles of pressure are expressed as the angles between directions of the speed and reactions. Pateikta reakcijų ir slėgio kampų analitinio nustatymo metodika, nagrinėjant paprasčiausią plokščią skriejiklio ir svirties lankstinį mechanizmą. Pateikta mechanizmo taškų pagreičių ir grandžių kampinių greičių nustatymo eilės tvarka. Atlikta sandaros grupės jėginė analizė. Normalinių reakcijų lankstuose lygtys išreiškiamos tiesių, nubrėžtų per tašką nurodyta kryptimi, lygtimis. Suminių reakcijų lankstuose lygtys išreiškiamos tiesių, nubrėžtų per du taškus, lygtimis. Slėgio kampai – kampai tarp greičių ir reakcijų krypčių. На примере шарнирного четырехзвенника рассмотрена методика аналитического определения сил реакций и углов давления. Представлена определенная последовательность для выражения ускорений точек механизма и угловых скоростей звеньев. Приведен силовой анализ для ассуровой группы. Уравнения нормальных составляющих реакций выражаются как прямые, проходящие через данную точку в заданном направлении. Уравнения полных реакций в шарнирах выражены как прямые, проходящие через две зад�����нные точки. Затем выражены углы давления как углы между направлениями скоростей и реакций. Document type: Article

Abstract

Current developments in Car2X communication technology provide the basis for novel driver assistance systems. To assess the impact of such a system on a group of cars approaching a non moving traffic jam, the driver behavior resulting from a system which supports anticipatory driving is modeled and used in a sub-microscopic traffic simulation. By equipping various percentages of a simulated group of cars with the model, the effect of the system on maximum deceleration and fuel consumption can be assessed. Finally the problems resulting from switching between different driver models are discussed. Document type: Part of book or chapter of book

Abstract

This paper demonstrates a novel car-following model based on driver or passengers’ comfort. As we know, hasty deceleration during emergency brake will cause passengers feel uncomfortable. According to the relationship between brake acceleration and people’s comfortable feeling, the comfortable model is setup. The model calculates the following car’s acceleration by measuring the distance between the following car and the preceding car, the velocity of the following car, and controls the car’s acceleration to make driver and passengers feel comfort. The paper combine the model with the pervasive computing concept, provoke the pervasive computing driver behavior modeling idea and turn it into reality to increase the adaptability and reliability of car’s parts, when car equipped with this device, the prospect is not only the assistant driver or comfortable driver are realized in the car-following circumstance, but also the whole car’s performance will be improved. Document type: Part of book or chapter of book

Abstract

International audience; Understanding the composition of the Internet traffic has many applications nowadays, mainly tracking bandwidth consuming applications, QoS-based traffic engineering and lawful interception of illegal traffic. Although many classification methods such as Support Vector Machines (SVM) have demonstrated their accuracy, not enough attention has been paid to the practical implementation of lightweight classifiers. In this paper, we consider the design of a real-time SVM classifier at many Gbps to allow online detection of categories of applications. Our solution is based on the design of a hardware accelerated SVM classifier on a FPGA board.

Abstract

The IMAGINE railway traffic noise source model is described, which is a further elaboration and completion of the Harmonoise model. Within the EU project Harmonoise, a model was proposed including most of the main railway noise sources. In the IMAGINE project, complete formulation was put forward taking all relevant physical sources but also main operating conditions into account, and default source data was proposed. At a given section of track with a given traffic flow, for each type of rolling stock, a combination of operating conditions and physical sources may occur. The operating conditions are constant speed, acceleration, braking, curving and stationary operation. The physical sources are rolling noise, impact noise, traction noise, curve squeal in points or curves, broadband or tonal braking noise and aerodynamic noise. The IMAGINE models for each physical source are presented and their relevance for each operating condition is discussed. Some examples of default input data are given and measurement methods to obtain source data are outlined.

Abstract

We report on a first field test in which miniaturized sensor motes were used to explore and inspect an operational pipeline by performing in situ measurements. The spherical sensor motes with a diameter of 39 mm were equipped with an inertial measurement unit (IMU) measuring 3-D acceleration, rotation, and magnetic field, as well as an ultrasound emitter. The motes were injected into the pipeline and traversed a 260-m section of it with the flow of water. After the extraction of the motes from the pipeline, the recorded IMU data were read out for the off-line analysis. Unlike dead-reckoning techniques, we analyze the IMU data to reveal structural information about the pipeline and locate pipe components, such as hydrants and junctions. The recorded data show different and distinct patterns that are a result of the fluid dynamics and the interaction with the pipeline. Using the magnetic data, pipe sections made from different materials and pipe components are identified and localized. A preliminary analysis on the motes’ interaction with the pipeline shows differences in pipe wall roughness and locates structural anomalies. The results of this field test show that sensor motes can be used as a versatile and cost-effective tool for exploration and inspection of a wide variety of pipelines.

Abstract

The introduction of urban rail transit and high performance/quality/capacity bus transit systems throughout the world has dramatically improved the mobility of residents of cities in which they operate. The objectives of this work are: to provide a technical resource for transit planners and designers in developing cities in their public transport capacity and performance analysis work irrespective of mode. This report recommends methods of achieving practical transit capacity during normally encountered operating conditions. Where capacity is influenced by a measure of dispersion of some characteristic such as stop dwell time or vehicle headway, this is also noted. The purpose of measuring capacity is not just to provide a measure of system capability to transport passengers but also to provide some insight into the effect of service and physical design on customer service quality. When the demand for a service exceeds its schedule design capacity, service quality deteriorates either due to overcrowding on vehicles or at station platforms or diminished ability of customers to board the next arriving transport vehicle since it is already fully loaded, increased dwell times and hence decrease revenue speeds. The importance of service quality in transit capacity analysis cannot be overstated. Transit operators should be mindful that the urban transportation marketplace is more competitive. While it might be technically possible to design a service using a loading standard of 7 or 8 passengers per square meter, a number of customers will find that level intolerable and will seek alternate means of travel including walking (in the case of short distance trips), riding with someone else, riding taxis or purchasing a motorcycle or car. Accordingly, such loading standards should be thought of as interim measures until higher capacity at lower crowding can be achieved. Document type: Book