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301.
Coastal managers have sought to enhance the collaborative inputs of stakeholder groups into management activities. Nonetheless, established organizational approaches have led to primarily consultative forms of engagement and constrained citizen involvement in formative activities. In Olympia, Washington, managers overseeing the Deschutes Estuary Feasibility Study (DEFS) implemented an innovative cooperative research planning initiative that diverged from conventional consultative processes. Stakeholders, rather than government officials, identified the research priorities for the socioeconomic component of this restoration feasibility study. This design method altered the traditional roles and responsibilities of different organizational actors, and the involvement of citizen groups in these formative activities changed the relationship between governmental and nongovernmental actors. Using conceptual frameworks from organizational sociology, this study develops insights into the behavior of the organizations involved with the DEFS cooperative planning effort, demonstrating how engaging stakeholders in formative research planning activities may foster new types of collaboration among coastal management organizations. 相似文献
302.
This article identifies a set of fuel saving strategies designed to meet the needs of vessel owners and operators, and describes how the strategies can be combined into a comprehensive programme. The strategies are developed from over sixty potential fuel saving measures grouped on the basis of commonness of purpose and interdependency. These criteria reflect the finding that implementing certain strategies is a prerequisite to the success of other strategies, and the success of some strategies generates a need to implement other strategies. Operational strategies identified include: developing crew motivation for active participation in energy efficiency improvement programmes; altering ship speeds; reducing auxiliary load on main propulsion plant; improved matching of ship capacities and cargo volume; reducing miles traveled; and maximizing use of electronic navigation and communications aids. Physical plant modification strategies identified include: optimizing for reduced ship speeds; fuel switching, blending and modifying; hydrodynamic improvements to the hull and propeller; and improving thrust. 相似文献
303.
B. Gepner C. Bojanowski L. Kwasniewski J. Wekezer 《International Journal of Automotive Technology》2014,15(4):581-591
The main objective of the presented study was to compare the effectiveness of two standard test procedures for evaluating bus roof integrity: the dynamic rollover test according to UN-ECE Regulation 66 (ECE-R66), and the quasi-static symmetric roof loading according the Federal Motor Vehicle Safety Standard 220 (FMVSS 220). Both tests were applied to a selected Paratransit Bus. The investigation was carried out primarily using a numerical study backed up by experimental validation tests on components and full scale rollover tests. A sensitivity analysis using LS-OPT? was performed to identify the most important structural components influencing the response of the bus in these two tests. The results obtained from this study show that the final outcome of the crashworthiness assessment of the selected paratransit bus depends on the selection of the evaluation standard. Although the two tests are used for the same purpose of roof integrity evaluation, their results are divergent and may lead to different conclusions. The paper presents a discussion on the effectiveness of both standards in evaluating the rollover crashworthiness. 相似文献
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305.
Jiechao Liu Paramsothy Jayakumar Jeffrey L. Stein 《Vehicle System Dynamics: International Journal of Vehicle Mechanics and Mobility》2018,56(6):853-882
This paper presents a nonlinear model predictive control (MPC) formulation for obstacle avoidance in high-speed, large-size autono-mous ground vehicles (AGVs) with high centre of gravity (CoG) that operate in unstructured environments, such as military vehicles. The term ‘unstructured’ in this context denotes that there are no lanes or traffic rules to follow. Existing MPC formulations for passenger vehicles in structured environments do not readily apply to this context. Thus, a new nonlinear MPC formulation is developed to navigate an AGV from its initial position to a target position at high-speed safely. First, a new cost function formulation is used that aims to find the shortest path to the target position, since no reference trajectory exists in unstructured environments. Second, a region partitioning approach is used in conjunction with a multi-phase optimal control formulation to accommodate the complicated forms the obstacle-free region can assume due to the presence of multiple obstacles in the prediction horizon in an unstructured environment. Third, the no-wheel-lift-off condition, which is the major dynamical safety concern for high-speed, high-CoG AGVs, is ensured by limiting the steering angle within a range obtained offline using a 14 degrees-of-freedom vehicle dynamics model. Thus, a safe, high-speed navigation is enabled in an unstructured environment. Simulations of an AGV approaching multiple obstacles are provided to demonstrate the effectiveness of the algorithm. 相似文献
306.
目的探讨肾康注射液对高血压肾损伤大鼠血压及相关指标的影响。方法将32只高血压肾损伤模型大鼠随机分为4组:模型对照组(即SHR组)、阳性对照组、肾康注射液大剂量组、肾康注射液小剂量组;WKY大鼠作为阴性对照组。阳性对照组腹腔注射给予福辛普利钠1.6mg/kg,肾康注射液大小剂量组分别腹腔注射肾康注射液,相当于生药剂量为4.8、2.4g/kg,阴性对照组和模型组腹腔分别注射等体积生理盐水,每天1次,连续给药30d。末次给药后检测高血压肾损伤大鼠的血压、心脏病变以及NO、Ang-Ⅱ、C反应蛋白、TGF-β1等指标。结果给药前后各组间大鼠体质量无明显差异(P>0.05);给药后肾康注射液组的血压值明显低于模型对照组,差异具有统计学意义(P<0.05或P<0.01);与模型对照组比较,肾康注射液组的NO活性明显增高,肾脏皮质中的Ang-Ⅱ明显降低,C反应蛋白明显降低,差异有统计学意义(P<0.05);但血清中的Ang-Ⅱ、血清转化因子TGF-β1无显著性差异(P>0.05)。结论肾康注射液能降低高血压肾损伤大鼠血压、提高肾组织的NO活性、降低Ang-Ⅱ及C反应蛋白的含量。 相似文献
307.
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309.
Wet multi-plate friction clutches are used in automotive drivelines to transfer torque, change gears, and prevent motion by
locking-up components in the transmission. The control strategy of starting is a crucial technology for the application of
a wet multi-plate friction clutch in the automotive industry. In this paper, a multi-state fuzzy control strategy for starting
is presented and applied to a continuously variably transmission (CVT) powertrain for the validation of this strategy. The
operation of the clutch was divided into four states: parking, starting, riding and emergency. The starting state was investigated
in detail. A fuzzy algorithm was employed to control the pressure of the hydraulic cylinder acting on the clutch. A distinguishing
feature is that the pressure does not increase but decreases to implement smooth starting during the initial period of starting.
The rapid-control prototype (RCP) of the wet friction clutch was developed to validate the new control strategy onboard a
test vehicle. Based on the experimental results, the multi-state control strategy for a wet friction clutch is a viable candidate
for engineering applications. 相似文献
310.
Model referenced adaptive control to compensate slip-stick transition during clutch engagement 总被引:1,自引:0,他引:1
Clutches are widely used in various vehicle powertrains. The engagement process of a friction clutch has three phases, i.e.,
open, slipping, and sticking. Transitions between different phases introduce a discontinuity to the powertrain dynamics, which
has been neglected in previous research. A model referenced adaptive controller (MRAC), based on Popov hyper-stability criterion,
is designed to compensate the discontinuity. MRAC adjusts the frictional torque along with the errors of the state variables
compared with those of a referenced model. The designed MRAC is applied to a clutch in a bus. Simulation and experimental
results under fast and slow startup cases show that MRAC can simultaneously reduce vehicle jerk and frictional dissipation
when compared with the conventional controller. 相似文献