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沈洁 《生物信息学》2018,25(6):124-129
作为一门以落地性为特征的应用型学科,对学生规划设计思维与能力的培养一直是风景园林专业教学的重要目标,如何通过教学有效地培养学生规划设计思维与能力也成为了风景园林专业教育关注的重要议题。本文从设计思维的特性出发,针对设计教学课程提出了一套控制方式和流程,并以同济大学本科三年级上学期的公园设计课程为例,对景观设计思维的培养途径和方法展开了教学尝试。  相似文献   

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The stepped wedge design (SWD) is a form of cluster randomized trial, usually comparing two treatments, which is divided into time periods and sequences, with clusters allocated to sequences. Typically all sequences start with the standard treatment and end with the new treatment, with the change happening at different times in the different sequences. The clusters will usually differ in size but this is overlooked in much of the existing literature. This paper considers the case when clusters have different sizes and determines how efficient designs can be found. The approach uses an approximation to the variance of the treatment effect, which is expressed in terms of the proportions of clusters and of individuals allocated to each sequence of the design. The roles of these sets of proportions in determining an efficient design are discussed and illustrated using two SWDs, one in the treatment of sexually transmitted diseases and one in renal replacement therapy. Cluster-balanced designs, which allocate equal numbers of clusters to each sequence, are shown to have excellent statistical and practical properties; suggestions are made about the practical application of the results for these designs. The paper concentrates on the cross-sectional case, where subjects are measured once, but it is briefly indicated how the methods can be extended to the closed-cohort design.  相似文献   

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The paper presents a detailed analysis of variance of PBIB designs supplemented by one or more standard treatments. Comparisons were carried out of treatment effects within the group of standard and test treatments and between the two groups. The analysis is supplemented by an example.  相似文献   

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黑曲霉纤维素酶高产固态培养基的快速优选研究   总被引:3,自引:0,他引:3  
研究采用正交设计,对影响黑曲霉 F_27产纤维素酶的 10个营养因素在较少水平下进行初选,从中选出对产酶影响显著的4个因素.在此基础上采用均匀设计,在较多水平下进行较少次数的试验,将试验结果用微机逐步回归处理,得到最优回归方程,由回归方程计算出预测极值点和预测极值、优化出高产纤维素酶固态培养基配方.经试验验证,试验实测值和预测值基本相符, CMCase活力平均达 3705U/g, FPA活力平均达 7.4U/g.表明对于多因子试验,应用正交设计结合均匀设计的试验方法是快速、简便、可行的.  相似文献   

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The incidence matrix of a BIB design for v treatments has been used to construct a biased spring balance weighing design. Conditions under which an optimum biased spring balance weighing design exists are given. It is also shown how this theory may be utilized to obtain treatment and experiment designs to estimate differences in legume content between pair of lines in an experiment overseeded with grass species.  相似文献   

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In this note it is shown that the block design with incidence matrix Ñ = [NNN], where N = c1hNh + coh (11′–Nh). coh and c1h are any non-negative integers and Nh,h = 1, 2,…,p, are incidence matrices of balanced incomplete block designs with the same number of treatments t, is a balanced block design with the block sizes exceeding the number of treatments. In derivation the matrix M0, introduced by CALIński (1971) is utilized.  相似文献   

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试验设计与数据处理在生物工程专业方向有着重要的应用,但是在本科教学中开设该课程的高校较少。本文结合生物工程中的常见案例,对该课程教学过程中常用的软件包括Excel、正交试验设计助手、Data processing system(DPS)和Design expert在单因素、多因素、正交、均匀、P-B(Plackett-Burman)和响应面等数据处理方法进行了探讨。通过比较分析各种软件和数据处理方法之间特点,增加该课程教学的实践性和应用性,从而提高教学质量。  相似文献   

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The dual of incomplete block designs has been studied with th́eir applications in genetical experiments. Partial diallel crosses (PDC) of type I have been constructed using balanced incomplete block (BIB) designs, partially balanced incomplete block (PBIB) designs and their dual designs. Simplified analysis of PDC has been presented using the dual property of these designs. List of optimal PDC having simple analysis has been given.  相似文献   

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This paper outlines methods of determining sample size for epidemiologic research in studies of the etiologic fraction. The basic model with a dichotomous disease and a single dichotomous exposure factor is considered. To determine sample size, the researcher must specify: the magnitude of the etiologic fraction ε to be detected as statistically significant, the level of significance α, the power 1 - β of the test, p the proportion of the population exposed to the risk factor and R the proportion of the population with the disease. Sample size formulas and tables are presented for the case-control, cohort and cross-sectional designs. Optimal allocation considerations are examined to minimize cost for a specified power. Extensive use is made of Walter's results concerning the asymptotic variance of the maximum likelihood estimator of the etiologic fraction for the three epidemiologic study designs.  相似文献   

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Nature is an information sourcebook of behaviour, function, colour and shape which can inspire visual design and invention. Studying the form and functional characteristics of a natural object can provide inspiration for product design and help to improve the marketability of manufactured products. The inspiration can be triggered either by direct observation or captured by three-dimensional (3D) digitising techniques to obtain superficial information (geometry and colour). An art designer often creates a concept in the form of a two-dimensional (2D) sketch while engineering methods lead to a point cloud in 3D. Each has its limitations in that the art designer commonly lacks the knowledge to build a final product from a 2D sketch and the engi- neering designer's 3D point clouds may not be very beautiful. We propose a method for Product Design from Nature (PDN), coupling aesthetic intent and geometrical characteristics, exploring the interactions between designers and nature's systems in PDN. We believe that this approach would considerably reduce the lead time and cost of product design from nature.  相似文献   

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KIEFER  J. 《Biometrika》1975,62(2):277-288
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