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71.
72.
In this paper we design a dynamic dictionary for
the priced information model initiated by Charikar et al. Assume that a set S consisting of n elements is given such that
each element has an associated price, a positive real number. The cost of performing an operation on elements of S is a function
of their prices. The cost of an algorithm is the sum of the costs of
all operations it performs. The objective is to design algorithms
which incur low cost. In this model we propose a dynamic dictionary, supporting
search, insert and delete, for keys drawn from a linearly ordered set.
As an application we show that the dictionary can be used in
computing the trapezoidal map of a set of line segments, a fundamental problem in
computational geometry. 相似文献
73.
新形势下的钻井信息化 总被引:3,自引:1,他引:2
介绍了我国石油行业在新的发展形势和管理模式下,钻井领域进行信息化的重要任务。在理清钻井业务流程的基础上,提出了以“钻井数据中心”为核心的钻井信息系统框架。从自动采集和人工采集两个方面阐明了钻井数据采集的范围和方式;从井筒网络、井场局域网、远程传输网和企业网等方面介绍了钻井信息化立体网络的构成,还介绍了钻井数据与甲方数据中心的数据交换方式、钻井数据中心的构建方法、以及钻井数据中心所支持的上层应用系统设计内容。提出了钻井信息化的发展方向,对我国钻井行业信息化有一定的指导意义。 相似文献
74.
75.
双螺杆反应挤出模型的研究 总被引:5,自引:0,他引:5
详细研究了双螺杆中反应挤出聚合物的动力学模型、流动模型和传热模型。通过实验得到了双螺杆反应器中聚合物的停留时间分布及平均停留时间。 相似文献
76.
MODELING LIQUID MASS TRANSFER IN HIGEE SEPARATION PROCESS 总被引:1,自引:0,他引:1
Correspondence concerning this paper should be addressed to Professor Richard S.H. Mah. Hsien-Hsin Tung is now affiliated with Department of Chemical Engineering, California Institute of Technology
Penetration theory is used to describe the liquid mass transfer in Higee separation process. Within a possible range of effective areas, it is shown that the predicted mass transfer coefficients are in reasonable agreement with the estimated mass transfer coefficients. The estimated coefficients were calculated from the experimental data and the possible effective areas. Hence it is concluded the penetration theory is generally applicable to describe liquid mass transfer in Higee separation process. The comparison also suggests that liquid mixing at the junctions of packing materials may be more complete in Higee process than in traditional process. 相似文献
Penetration theory is used to describe the liquid mass transfer in Higee separation process. Within a possible range of effective areas, it is shown that the predicted mass transfer coefficients are in reasonable agreement with the estimated mass transfer coefficients. The estimated coefficients were calculated from the experimental data and the possible effective areas. Hence it is concluded the penetration theory is generally applicable to describe liquid mass transfer in Higee separation process. The comparison also suggests that liquid mixing at the junctions of packing materials may be more complete in Higee process than in traditional process. 相似文献
77.
78.
马云辉 《微电子学与计算机》1998,15(6):48-51
本文采用信号流图法设计了一种基于OTA的三输入一输出多功能电压模滤波器新电路,该电路由五个OTA和两个接地电容构成,合理选择输入电压可实现低通、高通、带通、带阻及全通滤波功能。文章还对电路进行了MOS管级的计算机仿真,其结果表明所提出的电路方案正确有效。 相似文献
79.
80.
P. Powell 《Information Systems Journal》1992,2(4):269-280
Abstract. Expert systems proliferate. They are now a usable and used tool in a variety of organizations. However, little research has been undertaken on the quantification of success or failure of expert system projects. By and large the only test carried out for expert system validation is one of comparison of the conclusions of the system with those of an expert or team of experts. While questioning the validity, this paper accepts that this method is being used and analyses whether or not the results obtained from this type of test should be a surprise. That is, what sort of results should be expected and to what extent do the reported ones live up to these expectations? Earlier research from the field of human information processing casts doubts on the success claims made for current expert systems. The implications of this research are then analysed in order to explore the possible redeeming features of expert systems which are not taken into account in such comparisons. The use of linear models as comparators for expert systems may prove beneficial. 相似文献