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991.
In the present paper a vibrational differential equation governing on a rigid beam on viscoelastic foundation has been investigated. The nonlinear differential equation governing on this vibrating syst... 相似文献
992.
To solve the problem of the existing fault-tolerant control system of four-wheel independent drive (4WID) electric vehicles (EV), which relies on fault diagnosis information and has limited response to failure modes, a modelindependent self-tuning fault-tolerant control method is proposed. The method applies model-independent adaptive control theory for the self-tuning active fault-tolerant control of a vehicle system. With the nonlinear properties of the adaptive control, the complex and nonlinear issues of a vehicle system model can be solved. Besides, using the online parameter identification properties, the requirement of accurate diagnosis information is relaxed. No detailed model is required for the controller, thereby simplifying the development of the controller. The system robustness is improved by the error based method, and the error convergence and input-output bounds are proved via stability analysis. The simulation and experimental results demonstrate that the proposed fault-tolerant control method can improve the vehicle safety and enhance the longitudinal and lateral tracking ability under different failure conditions. 相似文献
993.
R. W. Botham 《运输规划与技术》2013,36(2):97-108
Based on an empirical analysis of the British road building programme the author concludes that the regional development effect of the highway building is small. Legislative influences such as limitation on driving hours and taxation measures may have a more significant influence on the economy. The road programme was found to have a centralizing effect on the distribution of employment. 相似文献
994.
M. Khaled M. Gad El Rab F. Hachem H. Elhage A. Elmarakbi F. Harambat H. Peerhossaini 《International Journal of Automotive Technology》2016,17(4):617-627
Fans are often tested without downstream blockage and, thus, the performance is considerably different when the fan is mounted in a vehicle as part of a cooling system and where high blockage effect is present downstream. The aim of the present work is to analyze by laser Doppler velocimetry LDV measurements the topology of the flow induced by a fan incorporated in a simplified underhood model reproducing engine blockage and to study the blockage effect of the engine positioning on the flow induced by the fan. The distance between the fan and the engine block affects the mean flow axial velocity U. The vertical velocity component W is greatly influenced by the variation of the distance between the fan and the engine block, both in magnitude and topology. 相似文献
995.
L. Lukacs M. Dassanayake R. Magalhaes C. Fontes M. Embirucu I. M. Pepe 《International Journal of Automotive Technology》2011,12(4):579-588
The vehicular illumination system has undergone considerable technological advances in recent decades such as the use of a Light Emitting Diode (LED) Adaptive Front-lighting System (AFS), which represents an industry breakthrough in lighting technology and is rapidly becoming one of the most important innovative technologies around the world in the lighting community. This paper presents AFS control alternatives using fuzzy logic (types 1 and 2) to determine its operating parameters taking into consideration the road conditions in the state of São Paulo (Brazil). Fuzzy logic is a well-known extension of the conventional (Boolean) logic that enables the treatment of uncertainty present in the information through the definition of intermediary membership values between the “completely true” and the “completely false”. This technique or modeling strategy is particularly important when a multi-parameter decision must be taken or the decisions are based on the human knowledge. The results show the potential of the methodology proposed and its suitability for light control providing safer nighttime driving. 相似文献
996.
C. Sánchez-Rebollo J.R. Jiménez-Octavio 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2015,53(3):392-401
This paper presents a detailed overview of CANDY, a catenary–pantograph dynamic interaction software. Authors describe the main key points of the formulation, focusing on its time-integration scheme, the pantograph and contact models as well as the solution of the initial equilibrium problem. Nonetheless one of the most important features of CANDY is its moving finite element mesh, which enables accurate results without excessive computational cost. The validation of the model against the European Standard EN 50318 and some conclusions and comments about the results of the benchmark are also included. 相似文献
997.
Entropy models are emerging as valuable tools in the study of various social problems of spatial interaction. With the development of the modelling has come diversity. Increased flexibility in the model can be obtained by allowing certain constraints to be relaxed from equality to inequality. To provide a better understanding of these entropy models they are analysed by geometric programming. Dual mathematical programs and algorithms are obtained. 相似文献
998.
L.R. Foulds 《Transportation Research Part B: Methodological》1981,15(4):273-283
There exist systems which can be usefully described by a network containingarcs through which a commodity of one type flows. This paper is concerned with finding a solution procedure for a particular multi-commodity flow network design problem. The problem is to identify a set of arcs in the network such that if travel is prohibited in them all flow travels by feasible paths and its total cost is minimal. The total flow in each arc may not exced its capacity, which is a known constant. Each arc and each node of the network has a non-negative constant unit traversal cost. Between each pair of distinct nodes there is a given non-negative rate of flow from the first vertex to the second which may be split up among a number of paths according to some constant traversal cost flow assignment process. The optimality criterion is the total traversal cost of all flow, which is to be minimized. Previous work on network design problems of this type is surveyed. The principal contribution of this paper is the presentation of a solution procedure for the above problem based on branch and bound enumeration. An illustrative numerical example is included. Computational experience gained in using the procedure with a FORTRAN IV program on an IBM 370 is favourable. 相似文献
999.
Silvana N.R. Birchenough Sin E. Boyd Roger A. Coggan David S. Limpenny William J. Meadows Hubert L. Rees 《Journal of Marine Systems》2006,62(3-4):204
This study presents the results of a trial assessment based on a combination of sampling techniques at a dredged material disposal site located off the North East coast of the UK, over 2001 to 2004. The site was surveyed with a high-resolution sidescan sonar system producing a mosaic with 100% coverage of the survey area. Benthic communities and sediments were ground-truthed using a Hamon grab with a video camera. Additionally, the area was also sampled in 2003 with a Sediment Profile Imaging (SPI) camera, which complemented other techniques by providing in situ information on sediment quality, and biogenic activities. An assessment is made of the benefits of combining the results from conventional methods, principally using grab samples, with those from acoustic techniques and optical imaging devices to determine seafloor and macrobenthic conditions. This information has the potential to contribute to the enhancement of routine monitoring programmes within UK waters. 相似文献
1000.
Corrosion of working chains continuously immersed in seawater 总被引:1,自引:0,他引:1
Robert E. Melchers Torgeir Moan Zhen Gao 《Journal of Marine Science and Technology》2007,12(2):102-110
Chains used in the offshore industry typically are exposed to continued high rates of corrosion, in part due to the working
of the chain not permitting a build up of protective rusts. Herein, a procedure is described for estimating the corrosion
loss of low-alloy steel chain under continued immersion corrosion conditions. The procedure is based on extensive recent investigations
of the effects of water temperature, salinity, water velocity, and surface roughness on steel corrosion under field conditions.
Since the working of the chain does not allow corrosion products (rust) to build up on the critical contact surfaces, erosion
due to wear and abrasion can be estimated separately. Two example applications are given. 相似文献