Showing papers by "Mobil published in 2017"

Bus travel time variability: some experimental evidences

Abstract: Bus travel time analysis is essential for transit operation planning. Then, this topic obtained large attention in transport engineering literature and several methods have been proposed for investigating its variability. Nowadays, the availability of large data quantities through automated monitoring allows more in-depth this phenomenon to be pointed out with new experimental evidence. The paper presents the results of some analyses carried out using automatic vehicle location (AVL) data of bus lines and automated vehicle counter (AVC) data on some corridors in the urban area of Rome where the bus services are mixed with other traffic and travel times are subject to high degrees of variability. The results show the effect of temporal dimension and similarity between travel time and traffic temporal patterns, and could open the road for the improvement of the short-term forecasting methods, too.

Piloter la métropole, une histoire de valeurs

Abstract: Piloter la metropole necessite de resoudre le decalage entre le territoire fonctionnel urbain et les differents territoires institutionnels qui la compose et donc de faire emerger un nouveau perimetre de l’action publique qui soit a l’echelle de l’aire metropolitaine. La mise en place d’un pilotage de cette aire metropolitaine est inevitablement conditionnee par le contexte, institutionnel et historique, dans lequel elle s’opere. La comparaison de pratiques entre deux contextes aussi eloignes que la France et la Suisse permet de s’extraire des particularismes regionaux et nationaux et de mieux cerner les enjeux partages. Une analyse des elements partages nous permet de proposer de structurer l’emergence de ce nouveau perimetre de l’action publique autour de trois voies paralleles et interdependantes que sont la creation d’institutions, la creation de projets et la creation de valeurs. Ces trois thematiques sont autant de points d’appui possibles permettant l’emergence d’un nouveau perimetre d’action publique a l’echelle de la metropole. Or il semble que, pris separement, aucun de ces points d’appui n’est en soi suffisant pour qu’emerge ce nouveau perimetre et que soit resolu le decalage entre les territoires fonctionnels et institutionnel. Un travail sur l’institution, sur le projet et sur les valeurs doit etre necessairement articule.

Laser processing device

Abstract: Disclosed is a laser processing apparatus for processing the surface of a workpiece by a laser beam, comprising a device head with an optical unit for imaging a laser beam onto a workpiece surface, a base station serving the device head with resources via electrical and fluid-carrying supply lines, a sealing cap which held the device head and can be applied with an encircling abutment edge on the values ​​piece surface, and a safety switch means which is actuated by pressing the sealing cap on the workpiece surface, wherein a first gas supply means supplying a first gas or gas mixture in a laterally limited by the sealing cap volume above the workpiece surface a second gas supply means supplies a second gas or gas mixture in a region above the delimited by the sealing cap, and a volume in the range of Gasabfuhreinrichtung the first and / or second gas or gas mixture discharges from the sealing cap limited volume.

Studi Surface Hardening pada Bahan Roda Gigi Buatan Indonesia dengan Menggunakan DC-Plasma Nitrocarburizing

Abstract: Material roda gigi buatan lokal Indonesia telah diteliti dan ditingkatkan kualitasnya dengan menggunakan alat DC-Plasma Nitrocarburizing buatan BATAN, Yogyakarta. Penelitian ini menggunakan waktu perlakuan yang bervariasi 1-5 jam dengan pemanasan 400 °C. Pengujian kekerasan dilakukan dengan menggunakan alat uji kekerasan Vicker, sedangkan pengamatan struktur mikro dilakukan dengan alat SEM dan EDS . Hasilnya menunjukkan bahwa kekerasan sampel awal adalah 177,88 HV, sedangkan sampel lokal yang dinitrocarburizing pada 400 °C selama 5 jam, kekerasannya adalah 328,96 HV. Hal ini sudah melebihi kekerasan material roda gigibuatan Jepang, yaitu 317,54 HV. Kata kunci: pengerasan permukaan, roda gigi, buatan Indonesia, DC-Plasma nitrocarburizing

Proposal of an accurate and low complexity method for frequency estimation using DFT interpolation

Abstract: The estimation of the frequency in a Discrete Fourier Transform (DFT) or Fast Fourier Transform (FFT) is a fundamental and well-studied problem in signal processing and communications. A variety of approaches to this problem, distinguished primarily by estimation accuracy, computational complexity, and processing latency, have been developed. For a signal containing an integer number of periods there are no differences in the application of the DFT algorithm and passing the representation of the waveform in the frequency spectrum and vice versa. Transform and reverse application generates errors only due to the calculation algorithm. The direct method to get a correct estimation of a peak frequency is to increase spectrum resolution up to the value of interest. But, unfortunately, this approach requires an additional processing time, which might be considered unacceptable, especially for portable systems without a powerful computing unit. A second solution to solve this problem is to implement a method to estimate the frequency value between spectral lines to correct dispersion effect due to the signal processing by Discrete Fourier Transform (DFT). The literature describes a number of methods to determine the estimate frequency of a spectral peak and its amplitude, but most of them involve a volume of high computation and enabling the calculation only are both the real and the imaginary parts of spectrum. This paper proposes a new frequency estimator, similar with another well-known algorithm, but more accurate having also a low computational complexity.

Electrohydraulic rear axle steering systems for agricultural vehicles

Abstract: The Lindner Tractor Factory produces small standard tractors from the type Lintrac 90 among other things. The main application areas of this tractor are the steep mountainand meadowlands in Austria, Switzerland, Southern Germany and Slovenia. Steep slopes, obstacles such as trees and rocks, as well as narrow roads through villages and towns are part of the daily work of the farmer there. The tractor can optionally be equipped with the rear axle steering Ehla Plus from Mobil Elektronik besides its comparably manageable total length of 3.5 m. 90 % of all customers choose this option. The front axle has a full steering angle of 52°. Hereby a turning circle diameter of 9.5 m is already achieved. With a rear axle steering angle of up to 20° this turning circle can be reduced to less than 7 m, FIGURE 1. This provides a highly manoeuvrability for the anyhow compact vehicle. When turning on the field the small turning circle reduces crop damage. Apart from that the field can be continuously used, FIGURE 2. A further advantage of the electrohydraulic rear axle steering is the easy parameter definition. Thereby, individual steering programs can be defined for the vehicle and used via the control panel. The switching between on-road mode and off-road mode is done via program selection. In addition to the steering programs the rear axle can also be adjusted manually via the control panel. In the following some steering programs are exemplary listed. – Manual steering: To prevent the drifting away of the rear of the tractor when driving parallel on a slope, the rear axle AUTHORS

Indoor and Outdoor Navigation in Smart Mobility Usage Scenarios

Abstract: Business and privately motivated journeys today are often driven by ad hoc decisions and a mix of different means of transport. A very distinct property of any mobility scenario that claims to be Smart is the fact that it needs to incorporate contextual and personal preferences during the selection process of a given means of transport at a given time and place. This results in great challenges, especially where different means of transport intersect, like at train stations, park and ride spots, parking garages, where travelers switch from one mode to another. In order to support a smooth transition, Smart Mobility systems need to allow for a seamless transition supported by an indoor-outdoor navigation solution. This chapter will highlight the different components needed to build up a seamless indoor-outdoor navigation solution, including spatial data management, indoor positioning, visualization of indoor maps, and a user-friendly turn-by-turn navigation. Furthermore, it will also discuss possible business models to justify the investments needed for an indoor-outdoor navigation system.

Simplified Frequency Offset Estimation for MIMO OFDM Systems

Abstract: This paper addresses a simplified frequency offset estimator for multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) systems over frequency selective fading channels. By exploiting the good correlation property of the training sequences, which are constructed from the Chu sequence, carrier frequency offset (CFO) estimation is obtained through factor decomposition for the derivative of the cost function with great complexity reduction. The mean-squared error (MSE) of the CFO estimation is derived to optimize the key parameter of the simplified estimator and also to evaluate the estimator performance. Simulation results confirm the good performance of the training-assisted CFO estimator.

The rescue of small rolled beams embedded in concrete bridge in Germany

Abstract: Iron sections embedded in concrete have been known from the beginning of the nineteenth century. This technology has been widely applied ever since and has proven to be a reliable technique for bridges with small spans. Nevertheless, the consideration of the bond between steel and concrete and the transverse load distribution of such structures has remained a broadly discussed topic among engineers. Demolition of a small German road bridge constructed in 1949 with this method was looming, as a conventional reassessment failed to provide the required load-bearing capacity. In an effort to save this historic bridge, the actual structural behaviour of the bridge was investigated by in situ testing. Displacement transducers and strain gauges mounted on selected steel beams recorded the behaviour during the application of static as well as travelling loads. Based on these results, the model for the transversal load distribution could be revised; thus, the bridge fulfilled the requirements after all.