高斯函数拟合参数选取标准的确定

在水深测量中由于水深数据的离散化特征,需要进行数据拟合,求得未知区域的海底地形。针对高斯函数与协方差函数之间的密切联系,对高斯函数移位的线性组合拟合的基本形式进行了较全面的分析。首先,利用协方差函数旋转面等概念分析了高斯函数的拟合条件及其参数的初步确定;其次,利用高斯函数衰减较快的特性,提出了比值函数准则确定参数的数学方法,并从理论上剖析了参数选择的数学本质,得到了参数选取的有效区间。最后通过大量的实际数据计算,得到了与理论相一致的结果,提高了高斯函数拟合的效率和精度。

Critical Buckling of Drill Strings in Cylindrical Cavities of Inclined Bore-Holes

Notwithstanding the fact that the problem of drill string buckling （Eulerian instability） inside the cylindrical cavity of an inclined bore-hole attracts attention of many specialists, it is far from completion. This peculiarity can be explained by the complexity of its mathematic model which is described by singularly perturbed equations. Their solutions （eigen modes） have the shapes of boundary effects or buckles （harmonic wavelets） localized in zones of the bore-hole that are not specified in advance. Therefore, the problem should be stated in the domain of entire length of the drill string or in some separated part including an expected zone of its buckling. In the paper, a mathematic model for computer analysis of incipient buckling of a drill string in cylindrical channel of an inclined bore-hole is elaborated. The constitutive equation is deduced with allowance made for action of gravity, contact, and friction forces. Computer simulation of the drill string buckling is performed for different values of the bore-hole inclination angle, its length, friction coefficient, and clearance. The eigen values （critical loads） are found and modes of stability loss are constructed. The numerical results for the case when the inclination angle equals friction angle coincide with ones obtained analytically.

THE APPLICATION OF THE COMPUTER AIDED ANALYSIS IN THE DESIGN OF COALMINE MACHINERY LINKAGES

This paper gives and verifies a mathematical model with only one argument which determines the movement parameters of any point in a plane four-bar linkage on the basis of the analysis of mining machinery linkages. C A A (computer aided analysis) based on the mathemetical model can be used to make not only the quick and accurate analysis and design of mining machinery linkages but also the movement analysis and optimization design of any other plane four-bar linkage.

Discipline progress of mineral mapping of gold deposit in China

Sanjiang and Jiaodong areas are the important gold regions in China.The gold mineralization is correlated with the Mesozoic faults and its derivative faults in the granite or the contact zone between granite and base rock.The mineral mapping is one of the important approaches of prospecting mineralogy.The temporal and spatial band distribution of mineral,mineral combination and mineral typomorphism features are natural regularity rules,but this kind of band feature is sometimes hidden and thus in need of mineral typomorphism research and mapping to disclose this band feature and to serve for the prospecting of mineral.The changes of the mineral typomorphism feature are often embodied in the"through"mineral,the typomorphism features of the through mineral change like the gradient toward the ore body,and the changes of the features are most obvious and strongest toward the orebodies.The new American mineralogy mapping indicates the weak change of the mineral composition or structure will lead to the change of the shape and wave length position of the specific absorbent feature.Australian experiment lab investigation has held the reason of a series of mineral.The progress achievement of the remote sensing and computer analysis technology now permits a direct comparison directly between the lab and remote sensing data,so the good feature database of the experiment light spectroscopy can serve for drawing of the spacial distribution and remote sensing material.Mineralogy mapping raised the extensive emphasis in the international earth arena.

Durum Wheat Bread： Old Sicilian Varieties and Improved Ones

In Mediterranean countries and particularly in Southern Italy, durum wheat （Triticum durum Desf.） is traditionally used for bread production. Market globalization has created, also in these regions, the spread of bread made with soft wheat flour （Triticum aestivum L.） standardizing this product flattening consumers＇ taste. With the aim of re-evaluating the old Sicilian local varieties, some landraces, chosen from the genebank of the institute, have been multiplied on farmers＇ fields to have enough material for making bread and for comparing this product with bread made by improved new varieties. Before milling in the pilot plant, the different wheats were characterized for their merceological indexes. The semolina obtained was analyzed for its chemical parameters. Rheological tests were conducted on dough and, finally, using standardized methods, one-variety breads were produced. On the bread slices, computerized image analysis was performed to measure colour and morphological parameters of crumb and crust. Sensory analysis, achieved through a descriptive profiling test, was conducted with trained judges using touch, fragrance and taste attributes for the different bread types. The different merceological, chemical and theological properties of raw material, grain and semolina were reflected in the breads prepared using old or improved varieties. Finally, the data obtained pointed out that the bread prepared with old and improved varieties can be clearly distinguished both by objective morphological parameters （image analysis） and by sensorial evaluations, for a potential traceability of typical product.

Empirical Likelihood of Density Function for Dependent Series

With the application of the special properties of strongly stationary m-dependent series,this paper is concerned with the empirical likelihood confidence intervals of density func- tion under m-dependent series.The limit distribution of empirical likelihood ratio statistics is given out,and the empirical likelihood confidence intervals of parameters can be constructed.A simulation study is conducted to show the finite sample performance of the empirical likelihood based method.