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101.
K. T. R. Van Ende D. Schaare J. Kaste F. Küçükay R. Henze F. K. Kallmeyer 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2016,54(10):1362-1383
For steer-by-wire systems, the steering feedback must be generated artificially due to the system characteristics. Classical control concepts require operating-point driven optimisations as well as increased calibration efforts in order to adequately simulate the steering torque in all driving states. Artificial neural networks (ANNs) are an innovative control concept; they are capable of learning arbitrary non-linear correlations without complex knowledge of physical dependencies. The present study investigates the suitability of neural networks for approximating unknown steering torques. To ensure robust processing of arbitrary data, network training with a sufficient volume of training data is required, that represents the relation between the input and target values in a wide range. The data were recorded in the course of various test drives. In this research, a variety of network topologies were trained, analysed and evaluated. Though the fundamental suitability of ANNs for the present control task was demonstrated. 相似文献
102.
F.?YangEmail author J.?Feng F.?Du 《International Journal of Automotive Technology》2016,17(4):629-637
A design approach for multi-speed automatic transmission with hybrid gear trains is proposed. The approach can be used to design automatic transmissions composed of planetary gear trains, fixed-axis gear trains or hybrid gear trains and the shifts follow the “one controlled part changing rule”. This approach consists of four parts: determining graphical configuration of the system using hypergraphs, analyzing power flow formulation, obtaining shifts configurations by shift searching algorithm, and determining physical configuration. A nine forward speed automatic transmission is analyzed to highlight the capacities of the proposed approach. The results have shown that the suggested approach is much clearer and less time consuming than the methods currently used. 相似文献
103.
Tae-Woo Lee Nam-Kyu Park John F. Joint Woong Gyu Kim 《Maritime Policy and Management》2000,27(2):133-144
There have been many efforts to develop a logistics information system in the Korean logistics industry. In spite of these efforts, there are many points which need improvement in the Logistics Information System, of which function is the electronic data communication without added value. This paper aims to describe some of the main problems and the successful factors which are being found in the evolution of the present EDI systems for clearing import/export container cargoes, with special reference to Singapore, Korea, and Japan. Following this, leaving legal issues aside, to suggest workable guidelines for designing a new efficient EDI system for container cargo logistics. As a result of the review, the following successful factors are drawn: (a) the planning, requirement analysis and design of EDI are critical, as it provides a framework for its implementation; (b) as the data of customs clearance are an integral part of a logistics EDI system, the inclusion of customs in the system design is essential; (c) the sharing system of cargo data as the framework of the logistics EDI is efficient for data interchange; (d) the EDI software for the user has been developed and provided by an EDI network operating company; and (e) to facilitate communication between trading partners and the transport sector, it is necessary to adopt a global message standard, such as EDIFACT. 相似文献
104.
One role often fulfilled by public administrators is to regulate private enterprise in the public interest. The academic literature has not developed this area fully because public administration is not always tasked with this function. Nevertheless, when regulation forms a part of the responsibilities of the public administrator, it is among the most important. An essential foundation for effective regulation is a complete understanding of the implications and impact of regulatory action. In the absence of regulation, entrepreneurial awareness is applied in the private sector exclusively to satisfying consumer wants. In a regulated market, the entrepreneur’s focus is shifted toward regulatory imperatives. Regulation offers non-market opportunities for entrepreneurial innovation, as well as imposing new market constraints. This paper examines regulation of the maritime industry by the US federal government as an example. 相似文献
105.
G. -Q. Liu Y. -C. Yan J. Chen F. -F. Xu 《International Journal of Automotive Technology》2010,11(4):573-580
A hydraulic power-assist system is a hydraulic regeneration system that can significantly improve fuel economy when installed
on a conventional bus operating in urban traffic. This paper presents a methodology for matching a new hydraulic power-assist
system (HPA) to a conventional bus. The HPA and the conventional bus were modeled using the AMESim environment. The HPA was
optimized using a simulation-based orthogonal design method with two indexes, the fuel economy and the acceleration performance.
According to the simulation results, the volume of the accumulator was the primary factor affecting fuel economy, and the
gear ratio of the transfer case was the primary factor influencing the acceleration performance. As a result, tradeoffs between
the two indexes are required for a practical operational scenario. Experimental results demonstrated that the optimal HPA
installed on a conventional bus was able to satisfy the acceleration performance requirement of the vehicle and also reduced
fuel consumption by 25 percent. 相似文献
106.
A. López J. Serrat C. Cañero F. Lumbreras T. Graf 《International Journal of Automotive Technology》2010,11(3):395-407
Detection of lane markings based on a camera sensor can be a low-cost solution to lane departure and curve-over-speed warnings.
A number of methods and implementations have been reported in the literature. However, reliable detection is still an issue
because of cast shadows, worn and occluded markings, variable ambient lighting conditions, for example. We focus on increasing
detection reliability in two ways. First, we employed an image feature other than the commonly used edges: ridges, which we
claim addresses this problem better. Second, we adapted RANSAC, a generic robust estimation method, to fit a parametric model
of a pair of lane lines to the image features, based on both ridgeness and ridge orientation. In addition, the model was fitted
for the left and right lane lines simultaneously to enforce a consistent result. Four measures of interest for driver assistance
applications were directly computed from the fitted parametric model at each frame: lane width, lane curvature, and vehicle
yaw angle and lateral offset with regard the lane medial axis. We qualitatively assessed our method in video sequences captured
on several road types and under very different lighting conditions. We also quantitatively assessed it on synthetic but realistic
video sequences for which road geometry and vehicle trajectory ground truth are known. 相似文献
107.
EricJ.Gonzales NikolasGeroIiminiS MichaelJ.Cassidy CarlosF.Daganzo 李长波译 WrittenbyEricJ.Gonzales NikolasGeroliminis TranslatedbyLiChangbo 《城市交通》2012,(3):81-90,22
从集计角度分析了运行多种交通方式的城市交通系统。利用目前已受关注的宏观基本图(简称MFD),描述城市交通的整体特性。以旧金山某区为例,使用现有数据,通过仿真论证如何应用MFD监管真实交通网络。然后讨论了同一路网中不同交通方式间如何相互作用,以及如何将这些作用纳入包含多种交通方式路网的MFD。研究得到的两个主要结论是:1)证实了已有研究猜想——对市区拥挤区域限行,可提高包括被限行者在肉的所有出行者的机动性;2)公交方式提供专用道路空间可提高所有交通方式的可达性。 相似文献
108.
Alba Martínez-López Alicia Munín-Doce Lorena García-Alonso 《Maritime Policy and Management》2013,40(6):608-631
Despite European Union (EU) political support to identify the most feasible Motorways of the Sea, the final decision can only be made by Private Shipping Companies, which are operators of a unique stretch of the intermodal chain. This paper provides a multi-criteria decision method to identify the most suitable Motorways of the Sea taking into account the competitiveness of whole intermodal routes versus the alternative of road transport from the loader’s perspective. The analysis is carried out assuming a ‘many-to-many’ transport model. Firstly indexes of time and cost were defined and evaluated for every available route in the model in accordance with a multi-criteria decision matrix. Secondly, through a Monte Carlo simulation a sensitivity analysis was carried out in order to evaluate the influence on the results of the forecast assumed to construct the matrix. The results obtained are not only quantitative, but also qualitative. The development of intermodal routes via Motorways of the Sea is especially relevant for the peripheral EU countries. Due to the relevance of the freight flow between France and Spain and the congestion of their connections through the Pyrenees, the method proposed was applied to the analysis of this particular case 相似文献
109.
This research study attempts to conceptualize models based on the relationship between characterization factors and port performance. By selecting a universe of the 230 largest European ports in terms of cargo throughput, 43 valid answers were obtained. Factor analysis and K–W (Kruskal–Wallis) tests were carried out taking as a reference the port performance theory. Findings reveal the existence of a relationship between port performance and its characterization factors, delving into the development of conceptualized models that contribute to deepen the knowledge of port competition structure and dynamics within Europe. 相似文献
110.
This paper presents an overview of the principles and technologies relating to railway infrastructure. Specifically this paper includes rail–wheel contact, inspection and maintenance of rail. Intelligent transport systems (ITS) and their applications for the purposes of the railway transport in Europe are discussed. The potential, levels of development, technological and operational characteristics of the European Railway Traffic Management System (ERTMS) are presented. Finally, a discussion on methodologies, principles and current practices for access charging in Europe is provided. 相似文献