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排序方式: 共有173条查询结果,搜索用时 365 毫秒
1.
模拟人工测量过程,设计了一种适用于气体测微传感器自动测量孔径的柔顺机构.该机构也适用于孔径分选以及小型轴类零件的自动装配等作业过程.  相似文献   
2.
大力发展农产品加工业提高农业市场竞争力   总被引:2,自引:0,他引:2  
加入WTO后,我省的农业结构调整进入了根本性变革的新阶段,除从农业内部着手外,更需要从农业之外寻找出路.做大做强农产品加工业将提高我省农产品竞争能力,农产品加工业的大发展将担负起优化结构,增加收入的历史重任.而要发展农产品加工业,必须实现六个方面的突破.  相似文献   
3.
Wide Diameters of Cartesian Product Graphs and Digraphs   总被引:1,自引:1,他引:1  
In graph theory and study of fault tolerance and transmission delay of networks, connectivity and diameter of a graph are two very important parameters and have been deeply studied by many authors. Wide diameter combining connectivity with diameter is a more important parameter to measure fault tolerance and efficiency of parallel processing computer networks and has received much attention in the recent years. Diameter with width k of a graph G is defined as the minimum integer d for which between any two distinct vertices in G there exist at least k internally disjoint paths of length at most d. In the present paper, the tight upper bounds of wide diameter of the Cartesian product graphs are obtained. Some known results can be deduced or improved from ours.  相似文献   
4.
In this paper, Abdelfatah and Mazloum's (2015) two-stage randomized response model is extended to unequal probability sampling and stratified unequal probability sampling, both with and without replacement. The extended models result in more efficient estimators than Lee et al.'s (2014) estimators of the proportion of the population having a sensitive attribute.  相似文献   
5.
从不均等选择概率的角度,提出两类常见的权数调整类型及其调整方法:一是规模调整,使得样本单元权数之和等于总体规模;二是结构调整,使得样本结构和总体结构一致,并构造出加权调整的设计效应模型,应用于复杂样本设计。案例分析显示,加权调整往往导致设计效应变大,带来负的效应,但校准调整能降低设计效应,提高估计精度。  相似文献   
6.
Given k( ? 3) independent normal populations with unknown means and unknown and unequal variances, a single-stage sampling procedure to select the best t out of k populations is proposed and the procedure is completely independent of the unknown means and the unknown variances. For various combinations of k and probability requirement, tables of procedure parameters are provided for practitioners.  相似文献   
7.
In estimating the proportion of people bearing a sensitive attribute A, say, in a given community, following Warner’s (J Am Stat Assoc 60:63–69, 1965) pioneering work, certain randomized response (RR) techniques are available for application. These are intended to ensure efficient and unbiased estimation protecting a respondent’s privacy when it touches a person’s socially stigmatizing feature like rash driving, tax evasion, induced abortion, testing HIV positive, etc. Lanke (Int Stat Rev 44:197–203, 1976), Leysieffer and Warner (J Am Stat Assoc 71:649–656, 1976), Anderson (Int Stat Rev 44:213–217, 1976, Scand J Stat 4:11–19, 1977) and Nayak (Commun Stat Theor Method 23:3303–3321, 1994) among others have discussed how maintenance of efficiency is in conflict with protection of privacy. In their RR-related activities the sample selection is traditionally by simple random sampling (SRS) with replacement (WR). In this paper, an extension of an essential similarity in case of general unequal probability sample selection even without replacement is reported. Large scale surveys overwhelmingly employ complex designs other than SRSWR. So extension of RR techniques to complex designs is essential and hence this paper principally refers to them. New jeopardy measures to protect revelation of secrecy presented here are needed as modifications of those in the literature covering SRSWR alone. Observing that multiple responses are feasible in addressing such a dichotomous situation especially with Kuk’s (Biometrika 77:436–438, 1990) and Christofides’ (Metrika 57:195–200, 2003) RR devices, an average of the response-specific jeopardizing measures is proposed. This measure which is device dependent, could be regarded as a technical characteristic of the device and it should be made known to the participants before they agree to use the randomization device. The views expressed are the authors’, not of the organizations they work for. Prof Chaudhuri’s research is partially supported by CSIR Grant No. 21(0539)/02/EMR-II.  相似文献   
8.
论述了一种成功运用于122cm背投式彩色投影电视机阴极射线管(CRT)中的磁聚焦电子枪。该枪采用了预聚焦发射系统和磁聚焦主透镜构成的双聚焦系统。经测试发现,当阴极电流为0.5~1.0mA时,其上屏束斑直径仅为0.065~0.080mm。  相似文献   
9.
为了比较汰渍、碧浪两种不同品牌洗衣粉的抑菌效果,本试验采用滤纸片琼脂平板扩散法,将待洲样品溶液转移至接种有大肠杆菌(Escherichia coli)、枯草芽孢杆菌(Bacillus Subtilis)和金黄色葡萄球菌(Staphylococcus aureus)敏感菌株的培养基上,经培养后测定其抑菌圈的大小,以判断其抑菌能力的强弱.通过对抑菌圈直径的比较和两个均数的差异显著性分析,发现汰溃、碧浪两种洗衣粉的押菌效果差异不显著.  相似文献   
10.
数控快走丝电火花线切割加工是一种应用较广泛的特种加工,本文详细阐述了确保该特种加工质量的几种方法。  相似文献   
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