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1.
The responsibility for managing coral reefs and other coastal resources was largely devolved to coastal municipalities and cities in the Philippines in 1991 with the passage of the Local Government Code. Devolution of powers and responsibilities to local government has paved the way for mainstreaming coastal resource management at the local level. However, the capacity to carry out this mandate has only recently begun to mature as municipalities and cities gain an increased awareness of the importance of coastal resources to communities and economic development. Approaches and strategies to increase local government capacity for coastal resource management are described based on the experiences of the Coastal Resource Management Project of the United States Agency for International Development. Qualitative and quantitative data are used to illustrate the possible impact of these capacity building efforts and to describe the current capacity of local government to undertake coastal resource management. After five years of project implementation, coastal municipalities have increased technical capacity, have allotted financial resources, and have achieved key performance benchmarks in the delivery of coastal resource management as a basic service. 相似文献
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3.
周贤全 《变流技术与电力牵引》2005,(4):37-41
介绍EH200型直流供电电力机车的开发.为证实机车性能满足基本要求,至2001年6月完成了样机试验,并从2001年7月至2002年3月牵引列车进行了运营.通过这些试验和运营,证实该种机车能满足规定的性能,包括与地面设施的匹配. 相似文献
4.
M. K. Verma T. D. Gillespie Associate Research Scientist 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1980,9(1):1-17
An analytical model is developed here for studying the roll dynamics of commercial vehicles. Large displacements and rotations are accounted for in this nonlinear model so that it can be used for the study of roll dynamics well beyond the limits of wheel lift-off. The model is used to illustrate some of the dynamic phenomena in vehicle rollover, especially the interactive coupling between the roll and the vertical modes of motion. The influence of suspension backlash on rollover resistance is demonstrated, and the phenomenon of roll motion resonance is illustrated to suggest new means for evaluating vehicle rollover sensitivity. 相似文献
5.
Y. -G. Kim C. -S. Jeon S. -W. Kim T. -W. Park 《International Journal of Automotive Technology》2013,14(6):903-911
The railway transportation system has much advantage in eco-friendliness, punctuality and safety compared to any other transportation system. Most of the railway system administrators have to control and operate under limited resources such as trains and facilities. It is necessary to control traveling time and energy consumption for efficient operation in the railway systems, because the board rate of passenger is inconstant with time variance. It is common that the shorter traveling time causes the greater energy consumption. In this study, a new optimization method considering operation time or energy consumption is proposed by using differential evolution algorithm and some cases are reviewed. The total energy change due to operation time variation are investigated by using the proposed optimization method for tangent and gradient track conditions. Both cases, the total energy decreases exponentially. However, because of gradient the total energy are saturated after a certain time for gradient track. 相似文献
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G. S. Jung Y. H. Sung B. C. Choi C. W. Lee M. T. Lim 《International Journal of Automotive Technology》2012,13(3):347-353
Although premixed charge compression ignition (PCCI) combustion engines are praised for potentially high efficiency and clean
exhaust, experimental engines built to date emit more hydrocarbons (HCs) and carbon monoxide (CO) than the conventional machines.
These compounds are not only strictly controlled components of the exhaust gas of road vehicles but are also an energy loss
indicator. The prime objective of this study was to investigate the major sources of the HCs formed in the combustion chamber
of an experimental PCCI engine in order to suggest some effective technologies for HC reduction. In this study, to explore
the dominant sources of HC emissions in both operation modes, a single cylinder engine was prepared such that it could operate
using either conventional diesel combustion or PCCI combustion. Specifically, the contributions of the top-ring crevice volume
in the combustion chamber and the bulk quenching of the lean mixture were investigated. To understand the influence of the
shape and magnitude of the crevice on HC emissions, the engine was operated with 12 specially prepared pistons with different
top-ring crevices installed one after another. The engine emitted proportionally more HCs as the depth of the crevice increased
as long as the width remained narrower than the prevailing quench distance. The top-ring-crevice-originated exhaust HCs comprised
approximately 31% of the total HC emissions in the baseline condition. In a series of tests to estimate the effects of bulk
quench on exhaust HC emissions, intake air was heated from 300K to 400K in steps of 25K. With the intake air heated, HC and
CO emissions decreased with a gradually diminishing rate to zero at 375K. In conclusion, the most dominant sources of HC emissions
in PCCI engines were the crevice volumes in the combustion chamber and the bulk quenching of the lean mixtures. The key methods
for reducing HC emissions in PCCI engines are minimizing crevice volume in the combustion chamber and maximizing intake air
temperature allowed based on the permissible NOx level. 相似文献
8.
Fast and predictive simulation tools are prerequisites for pursuing simulation based engine control development. A particularly attractive tradeoff between speed and fidelity is achieved with a co-simulation approach that marries a commercial gas dynamic code WAVE™ with an in-house quasi-dimensional combustion model. Gas dynamics are critical for predicting the effect of wave action in intake and exhaust systems, while the quasi-D turbulent flame entrainment model provides sensitivity to variations of composition and turbulence in the cylinder. This paper proposes a calibration procedure for such a tool that maximizes its range of validity and therefore achieves a fully predictive combustion model for the analysis of a high degree of freedom (HDOF) engines. Inclusion of a charge motion control device in the intake runner presented a particular challenge, since anything altering the flow upstream of the intake valve remains “invisible” to the zero-D turbulence model applied to the cylinder control volume. The solution is based on the use of turbulence multiplier and scheduling of its value. Consequently, proposed calibration procedure considers two scalar variables (dissipation constant C β and turbulence multiplier C M ), and the refinements of flame front area maps to capture details of the spark-plug design, i.e. the actual distance between the spark and the surface of the cylinder head. The procedure is demonstrated using an SI engine system with dual-independent cam phasing and charge motion control valves (CMCV) in the intake runner. A limited number of iterations led to convergence, thanks to a small number of adjustable constants. After calibrating constants at the reference operating point, the predictions are validated for a range of engine speeds, loads and residual fractions. 相似文献
9.
T. Y. Shin S. Y. Kim J. Y. Choi K. S. Yoon M. H. Lee 《International Journal of Automotive Technology》2011,12(1):103-110
This paper presents a modified lateral control method for an autonomous vehicle with both look-ahead and look-down sensing
systems. To cope with sensor noise and modeling uncertainty in the lateral control of the vehicle, a modified LMI-based H
lateral controller was proposed, which uses the look-ahead information of the lateral offset error measured at the front of
vehicle and the look-down information of the vehicle yaw angle error between the reference lane and the centerline of the
vehicle. To verify the safety and the performance of the lateral control, a scaled-down vehicle was developed, and the positioning
of the vehicle was estimated with USAT. The proposed controller, which uses both look-ahead and look-down information, was
tested for lane changing and reference lane tracking with both simulation and experiment. The simulation and experimental
results show that the proposed controller has better tracking and handling performance compared with a controller that uses
only the look-ahead information of the target heading angle error. 相似文献
10.
T. Katayama A. Aoki T. Nishimi 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》1988,17(4):211-229
The control behaviour of motorcycle riders is studied by means of a simulation model for the ridermotorcycle system, which stresses the control actions of the riders. The rider model describes the major steering torque control as well as the rider's own body control actions. This simulation model is applied to a single lane change maneuver and the results of this simulation are compared with the experiments in order to examine its validity. 相似文献