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81.
层状边坡渐进破裂与失稳过程数值模拟探讨 总被引:5,自引:0,他引:5
运用岩石破裂与失稳过程分析RFPA^2D系统,以含层理弱层边坡的渐进破裂与失稳分析为例,通过对边坡渐进破裂与失稳发生孕育机制及其锚固控制规律的数值模拟,数值模拟再现了含层理弱层和锚固边坡渐进破坏与失稳的发生、发展过程,模拟结果表明,复杂结构边坡的渐进破坏与失稳现象是一些简单机理的演化结果。 相似文献
82.
83.
This paper presents a system dynamics approach to simultaneous land use/transportation system performance modeling. A model is designed based on the causality functions and feedback loop structure between a large number of physical, socioeconomic, and policy variables. The model consists of 7 sub‐models: population, migration of population, household, job growth‐employment‐land availability, housing development, travel demand, and traffic congestion level. The model is formulated in DYNAMO simulation language, and tested on a data set from Montgomery County, MD. In Part I: Methodology, the overall approach and the structure of the model system is discussed and the causal‐loop diagrams and major equations are presented. In Part II: Application, the model is calibrated and tested with data from Montgomery County, MD. Least square method and overall system behavior are used to estimate the model parameters. The model is fitted with the 1970–80 data and validated with the 1980–1990 data. Robustness and sensitivities with respect to input parameters such as birth rate or regional economy growth are analyzed. The model performance as a policy analysis tool is examined by predicting the year by year impacts of highway capacity expansion on land use and transportation system performance. While this is a first attempt in using dynamic system simulation modeling in simultaneous treatment of land use and transportation system interactions, and model development and application are limited due to data availability, the results indicate that the proposed method is a promising approach in dealing with complex urban land use/transportation modeling. 相似文献
84.
85.
Nonlinear Robust Control of Torque Converter Clutch Slip System for Passenger Vehicles Using Advanced Torque Estimation Algorithms 总被引:3,自引:0,他引:3
Jin-Oh Hahn Kyo-Il Lee 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2002,37(3):175-192
In this paper, a torque-estimation-based robust controller for passenger car torque converter clutch slip system is presented. The proposed robust controller uses only the measurements available from inexpensive sensors that are installed in current passenger vehicles for torque estimation and feedback control. A conventional full state observer along with a neural-network-based open-loop hydraulic actuator observer is designed to estimate the unknown driving load, and a neural-network-based turbine torque estimator considering the temperature of oil circulating the torque converter is developed for improved turbine torque estimation accuracy. The stability of the internal dynamics is also investigated, and the performance and robustness of the robust controller is validated by simulation studies. 相似文献
86.
Seung-Ho Yang Sang-Beom Lee Jung-Ho Park Seung-Yoon Han Young-Myung Choi Jitae Do Sun-Hong Kwon Bernard Molin 《Journal of Marine Science and Technology》2016,21(4):715-728
An experimental study was performed on the piston- and sloshing-mode moonpool resonances of offshore structures. Two different geometries were considered to investigate the flow characteristics in a plain moonpool and a moonpool with a cofferdam. To examine the efficiency of a cofferdam for reducing the flow in a moonpool, three cofferdam geometries were tested. The plain moonpool presented violent flows as a result of the piston- and sloshing-mode resonances. However, the moonpool with the cofferdam introduced violent sloshing waves instead of the ascent and descent of the water column in the piston-mode moonpool resonance. Among three different cofferdam geometries, the model with a right triangle facing to the left on the top of the cofferdam was most effective in reducing the flow in the moonpool when compared with the other models. 相似文献
87.
In this paper, the basic architecture of an agent is proposed and a federated agent system based on the basic architecture
is implemented. The basic architecture consists of a knowledge query and manipulation language (KQML) handler, a knowledge
interchange format (KIF) interpreter, and design flow control codes. The KQML handler is a module for managing KQML performatives
received from an agent. The KIF interpreter provides the support services of content-based routing, translation using a matching
scheme, and simple inference. A Java template package was used for communication between agents. A federated agent system
was then applied to a preliminary ship design to show the handling process of the agent system and its applicability in a
distributed design environment.
Received: June 5, 2000 / Accepted: September 20, 2000 相似文献
88.
89.
Assessing machine’s performance through comparing the same or similar machines is important to implement intelligent maintenance
for swarm machine. In this paper, an outlier mining based abnormal machine detection algorithm is proposed for this purpose.
Firstly, the outlier mining based on clustering is introduced and the definition of cluster-based global outlier factor (CBGOF)
is presented. Then the modified swarm intelligence clustering(MSIC) algorithm is suggested and the outlier mining algorithm
based on MSIC is proposed. The algorithm can not only cluster machines according to their performance but also detect possible
abnormal machines. Finally, a comparison of mobile soccer robots’ performance proves the algorithm is feasible and effective. 相似文献
90.
Fuel economy comparison of conventional drive trains series and parallel hybrid electric step vans 总被引:1,自引:0,他引:1
S. B. Han Y. H. Chang Y. J. Chung E. Y. Lee B. Suh A. Frank 《International Journal of Automotive Technology》2009,10(2):235-240
A hybrid electric vehicle (HEV) is a vehicle that combines a conventional propulsion system with an on-board rechargeable
energy storage system to achieve better fuel economy than a conventional vehicle HEVs do not have limited ranges like battery
electric vehicles, which use batteries charged by an external source. The different propulsion power systems may have common
subsystems or components. The objective of this study is to compare the fuel economies of a conventional step van, a series
hybrid electric step van (HESV), and a parallel HESV by calculating the fuel consumption using the ADVISOR software by NREL.
We also showed the results of the vehicles in different driving cycles including the Central Business District bus cycles,
the New York City Cycle, and the US EPA City and Highway cycles. 相似文献