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111.
In this paper, in allusion to the three kinds of serious overvaluation (the budgetary estimate of project construction exceeds the rough estimate, the budget exceeds the budgetary estimate and the final accounts exceed the budget) causing uncontrollable project investment often appeared in domestic project construction,the main causes for that are analyzed. That is, the frequent project change and the malpractice of the cost managing system. In this paper, according to some real projects,the kinds and causes of project change are clarified and the malpractice of the cost managing system is analyzed. The effective approaches of reducing the project change, especially the united surveying and improving the cost managing system in order to make the effective control of the project investment are realized. 相似文献
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In this paper,by the use of Farkas lemma and its inve-rse proposition,the generalized Kuhu-Tuoker conditions for the existanceof strong minimum point in differential multiobjective programming inBanach spaces and the existance of sufficient condition of weak Paretominimum Foint are derived. 相似文献
114.
针对国内汽车企业不具备整车齐全的三维CAD模型的实际情况,提出一种基于动态装配图热点和产品结构树结点双向驱动的备件数据可视化管理方案,在Delphi开发平台上将Action Script技术和ActiveX技术集成到可视化备件管理系统中。详细阐述了图热点驱动和树结点驱动的程序实现流程.给出了动态装配图、装配结构树和界面数据窗三者之间的联动关系,实现两种驱动的等效性。为了便于用递归算法遍历结构树,对复杂网状结构的零部件从属依赖关系进行规范化处理.使之成为树形结构。采用约束递归迭代,对一次性加载零部件的层数和范围进行约束,用统一的虚拟临时结点代替当前非叶子结点的子结点,实现整车装配关系结构树构造过程的优化。 相似文献
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117.
随着我国综合国力的稳步发展,城乡人民的生活水平也不断提高,发展瓯柑种植面积和提高产量,改善瓯柑品质,是人们物质生活的需要,也是我国新形势下农业产业结构调整的发展趋势,并带动山区农民共同致富,利国又利民。本文就温州地区发展山园瓯柑节水喷灌机械配套节本增效技术进行叙述,对于推广应用具有重要的现实意义。 相似文献
118.
Three trickle irrigation schedules, two of which were scheduled according to soil water potential ( soil) (tensiometer method) and daily stem contraction (DSC) (dendrometer method) respectively and the other one was a schedule of restricted water supply, were applied to a mature peach orchard.The annual water application based on soil was greater than that based on DSC. However, tree growth, fruit size and leaf water potential (leaf) on the trees in the dendrometer scheduling plot did not differ from those in the tensiometer scheduling plot while the premature fruit drop and fruit bud initiation were greatly different. The restricted water supply treatment limited significantly both tree and fruit growth. In addition, the lower leaf was observed on the trees in this plot.Further study shows that use of the dendrometer method for scheduling irrigation satisfies the water needs of the plant and that the tensiometer method is less accurate.Abbreviations leaf
leaf water potential
- soil
soil water potential
- DSC
daily stem contraction
- LVDT
linear variable displacement transducer
- PET
potential evapotranspiration 相似文献
119.
使用迭代重加权最小二乘法求解平面度误差 总被引:1,自引:0,他引:1
提出了几何误差评定的迭代重加权最小二乘(IRLS-Iterative Reweighted Least Squares)算法。该算法采用一个迭代过程求解一系列加权最小二乘问题,并在每一步迭代中按照一定的规则对权系数进行调整,使其逐步逼近最优拉格朗日乘子。对于用CMM(坐标测量机)和其他设备得到的数据,可得到平面度误差的精确值。 相似文献
120.
Poor functioning of theirrigation system in Pakistan has been asource of concern for the last few decades,during which time it has been the subject ofconsiderable external assistance andinternal policy reforms. Consequently, thegovernment of Pakistan introducedinstitutional restructuring in irrigationand drainage subsectors to impartnecessary improvements. Under thesereforms, management at secondary canallevel has recently been handed over to theFarmers Organizations (FOs) of selecteddistributaries in pilot areas. This studywas designed to evaluate a farmer-manageddistributary in southern Punjab. Fieldmeasurements revealed that hydraulicaspects of the irrigation service deliveredby the FO management has been significantlyimproved and as a result highlyproportionate and equitable waterdistribution was observed, particularly atthe tail reaches of the distributary. Dueto effective FO management farmers'interventions to increase the outletdischarge by illegal means has been almosteradicated. As a result of theseimprovements imparted by the FO in systemmanagement, the extent of irrigated area hasincreased on average by 6 to 7%, evenunder severe drought-like conditionsprevailing in the country during recentyears. Further cost recoveries haveincreased by an amount of 14% for summerand 23% for winter growing seasons,respectively, from the irrigated area of thedistributary. Thus experience from Hakra4-R distributary has shown that even underundesirable natural circumstancesIrrigation Management Transfer (IMT) wasquite effective in achieving the keytargets of the institutional reformslaunched at pilot scale in the country. 相似文献