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121.
122.
张新海 《焦作师范高等专科学校学报》2007,23(3):69-70
利用MAX232芯片,实现了上位PC机与AT89C52单片机之间的通信,其中上位机的程序设计主要采用Visual C 。使用MSComm控件的属性、方法和事件,最后给出了一个实现串行数据通信的主要程序。 相似文献
123.
张超英 《贵州科技工程职业学院学报》2007,2(2):53-56
探讨了高职院图书馆的现状,提出了高职院图书馆发展的方向,并论述了高职院图书馆的定位问题,最后对图书馆信息资源的建设进行了思考。为建设一个高效、便利的高职院图书馆提供一种思路。 相似文献
124.
文章介绍了黄土湿陷性试验的两种试验方法,对黄土湿陷机理作了简要分析,并对双线法的误差及其修正进行了讨论。 相似文献
125.
文章介绍了为提高物理课堂的教学效果,要充分调动物理课的“本味”和“趣味”,达到学生爱学、乐学的目的。 相似文献
126.
127.
Rein Vihalemm 《Foundations of Science》2007,12(3):223-234
The philosophical analysis of chemistry has advanced at such a pace during the last dozen years that the existence of philosophy of chemistry as an autonomous discipline cannot be doubted any more. The present paper will attempt to analyse the experience of philosophy of chemistry at the, so to say, meta-level. Philosophers of chemistry have especially stressed that all sciences need not be similar to physics. They have tried to argue for chemistry as its own type of science and for a pluralistic understanding of science in general. However, when stressing the specific character of chemistry, philosophers do not always analyse the question ‘What is science?’ theoretically. It is obvious that a ‘monistic’ understanding of science should not be based simply on physics as the epitome of science, regarding it as a historical accident that physics has obtained this status. The author’s point is that the philosophical and methodological image of science should not be chosen arbitrarily; instead, it should be theoretically elaborated as an idealization (theoretical model) substantiated on the historical practice of science. It is argued that although physics has, in a sense, justifiably obtained the status of a paradigm of science, chemistry, which is not simply a physical science, but a discipline with a dual character, is also relevant for elaborating a theoretical model of science. The theoretical model of science is a good tool for examining various issues in philosophy of chemistry as well as in philosophy of science or science studies generally. 相似文献
128.
Global Optimization in Any Minkowski Metric: A Permutation-Translation Simulated Annealing Algorithm for Multidimensional Scaling 总被引:3,自引:1,他引:2
It is well known that considering a non-Euclidean Minkowski metric in Multidimensional Scaling, either for the distance model
or for the loss function, increases the computational problem of local minima considerably. In this paper, we propose an algorithm
in which both the loss function and the composition rule can be considered in any Minkowski metric, using a multivariate randomly
alternating Simulated Annealing procedure with permutation and translation phases. The algorithm has been implemented in Fortran
and tested over classical and simulated data matrices with sizes up to 200 objects. A study has been carried out with some
of the common loss functions to determine the most suitable values for the main parameters. The experimental results confirm
the theoretical expectation that Simulated Annealing is a suitable strategy to deal by itself with the optimization problems
in Multidimensional Scaling, in particular for City-Block, Euclidean and Infinity metrics. 相似文献
129.
张锐梅 《哈尔滨师范大学自然科学学报》2008,24(4)
研究可分拟满Steiner树的结构性质与最优可分拟满Steiner树的生成算法. 相似文献
130.
LIU JianCai XU JiaKai NING XinBao TIAN Run 《科学通报(英文版)》2007,52(17):2438-2442
The characterization of non-stationary signal requires joint time and frequency information. However, time and frequency are a pair of non-commuting variables that cannot constitute a joint probability density in the time-frequency plane. The time-frequency distributions have difficult interpretation problems arising from negative and complex values or spurious components. In this paper, we get time-frequency information from the marginal distributions in rotated directions in the time-frequency plane. The rigorous probability interpretation of the marginal distributions is without any ambiguities. This time-frequency transformation is similar to the computerized axial tomography (CT or CAT) and is applied to signal analysis and signal detection and reveals a lot of advantages especially in the signal detection of the low signal/noise (S/N). 相似文献