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71.
72.
对数控加工所获得的叶轮流道的加工误差进行仿真。首先对刀位轨迹线进行归一化处理,以此计算出脊棱高度曲线,再采用线性插值的方法得到曲面上采样点的加工误差。由于自由曲面加工中的刀位点比较密集,本文利用彩色云图将加工误差可视化,完善了对数控加工结果的计算机几何仿真。该算法已在自行研制的叶轮CAM系统中得到验证,并且与实际加工结果一致。 相似文献
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74.
This paper reports the outcomes of a deliberative workshop comparing land-use plans proposed by land-manager or domain experts with those derived using a computer-based decision support system (DSS). The DSS integrates four main components, a geographic information system, land-use systems simulation models, impact assessments and land-use planning tools. The land-use planning tools draw on the other components to generate and evaluate alternative patterns of land use and management. Since the land-use planning tools are based on multi-objective genetic algorithms (mGAs) it is possible to generate a range of alternative plans that define the structure of the trade-off between the objectives. The workshop tasked the delegates with specifying land-use plans that achieved the best compromise between two objectives known to be non-commensurable and conflicting. The nature of the best compromise was dependent on their individual perspectives. The delegates proposed allocations both as individuals and in researcher-facilitated sub-groups. The mGA allocations were then compared with those derived by delegates and were found to be broadly similar in performance. Differences in the range of allocations considered feasible were explained by the hard and soft constraints on allocations agreed between the delegates and articulated within the workshop process. The hypothesis that part of the difference in performance between the mGA and delegate allocations was due to the delegates blocking together fields with the same land use for convenience of management was proved. The analysis of the group allocations revealed that the decision-making process had failed to improve on the individual allocations. From these results it was concluded that there was a potential role for mGA based land-use planning tools in researching into, and deliberating on, the possible impacts of policy or other factors affecting land-use systems. It was further concluded that the tools should not be used in isolation since there was the need for stake-holder inputs to adequately define the range of feasible and practical land-use plans. 相似文献
75.
Remotely sensed (RS) data is a major source to obtain spatialdata required for hydrological models. The challenge for thefuture is to obtain besides the more direct observable data(landcover, leaf area index, digital elevation model andevapotranspiration), non-visible data such as soilcharacteristics, groundwater depth and irrigation practices.In this study we have explore the option of using inversemodeling to obtain these non-RS-visible data. For a commandarea in Haryana, India, we applied for the 2000–2001 rabiseason a RS-GIS-combined inverse modeling approach to derivenon-RS-visible data required in the regional application ofhydrological models. A Genetic Algorithm loaded stochasticphysically based soil-water-atmosphere-plant model (SWAP) wasdeveloped for the inverse problem and used in the study. Theresults showed good agreement with the inventoried data suchas soil hydraulic properties, sowing dates, groundwaterdepths, irrigation practices and water quality. The deriveddata could be used to predict the state of the system at anytime in the cropping season, which can be used to evaluateoperational management strategies. 相似文献
76.
平面梯形机构不能精确实现无侧滑转向的证明 总被引:3,自引:0,他引:3
基于“转向机构不可能精确实现无侧滑转向”的预先判断,多年来人们对轮式车辆各种转向机构做了大量优化设计工作。然而迄今为止没研究过该判断是否正确。转向机构中最具代表性的整体式等腰梯形机构常被简化为平面等腰梯形机构进行设计。在此情况下,本文通过将实际转向角方程和无侧滑方程对比,证明上述判断是正确的,即该种平面机构不能使车辆在任意转弯半径下都做精确的无侧滑转向。这一结论为平面等腰梯形转向机构的近似和优化设计提供了理论依据。 相似文献
77.
遗传算法在离心泵叶片优化设计中的应用 总被引:2,自引:3,他引:2
对遗传算法在流体机械优化设计中的应用现状作了较为全面的总结;提出了将遗传算法应用于离心泵叶片优化设计中,分析了遗传算法在离心泵优化设计中应用的可行性以及存在的问题;对离心泵优化设计的发展提出了一些新建议和尝试。 相似文献
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79.
在电力系统中,由于开关容量及运行方式限制,通常在低压系统中多采用1段母线、1台变压器运行方式。为了避免这种运行方式在母线检修、故障时可能造成停电的缺点,因此可用断路器将单母线分段。母线经断路器分段后。对重要用户可以从不同段引出两个回路,有两个电源供电。母线分段的数目。可以根据电源数目和容量来分.段数越多,停电的范围越小,所需电气设备越多.一般以4~6段为宜。本文对此配电母线进行N级联锁推导其算法.有利于今后解决多级联锁的问题。 相似文献
80.
遗传神经网络在温室黄瓜霜霉病预测中的应用 总被引:5,自引:0,他引:5
在神经网络结构的优化、连续权重的训练中采用遗传算法的方法对日光温室黄瓜霜霉病进行预测,并对其发生程度进行了拟合,计算值与实际值接近,表明该模型具有良好的预测效果。 相似文献