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1.
Gerechte designs are row and column designs which have an additional blocking structure formed by spatially compact regions. In this paper, and a companion paper (B ailey et al. 1990) we consider the correct analysis of these designs. In this paper we discuss the purpose of gerechte designs, and we note that the regions are not orthogonal to the rows and columns. This means that the usual sums of squares for rows, columns and regions are not additive. We show how the correct analysis can be performed, either through the use of appropriate formulae, or by the use of a statistical package. In the companion paper we show that the correct analysis cannot be justified by a randomization argument, and we outline other developments in analysis and design that may be more satisfactory. 相似文献
2.
This study illustrates the importance of randomization using two hypothetical field trials, one with a marked systematic trend and the other with a more erratic spatial pattern. The insights from these two examples are reinforced by analysis of a uniformity trial and a small simulation study. Results illustrate that both model‐based spatial analysis and randomization‐based analysis assuming independent errors are valid with full randomization but may be invalidated when randomization is lacking. It is concluded that randomization provides protection against different forms of spatial trend. The examples given in the study serve as a general reminder that agricultural experiments should be randomized whenever possible. 相似文献
3.
B. Yu. Anoshenko 《Euphytica》1996,90(2):149-162
Summary Presented are the results of an application of the local adjustment Field-method in the analysis of the real field experiments without replications and in experiments with pseudo- and random replications. It was found that the local adjustment allowed a more precise estimation of the real values of genotypes in all kinds of experiments over a wide interval of spatial heterogeneity. The results obtained indicate that by simply using up to 5 random replications the decrease of the spatial effects is inadequate for fields with medium and high soil heterogeneity or with unsuccessful randomization. The Field-method which has sufficient precision in evaluating spatial heterogeneity, considerably increases the reliability of estimates in experiments even with a small number of replications or with unsuccessful randomization. Therefore, for all field experiments that have fulfilled the necessary requirements the Field-method is recommended as an obligatory statistical procedure for a prior data analysis as it allows an accurate estimation of the real character expression of genotypes, as well as the random variance in experiments without replication and the parameters of ANOVA in ones with pseudo- and random replications. 相似文献
4.
Repeated measurements on the same experimental unit are common in plant research. Due to lack of randomization and the serial ordering of observations on the same unit, such data give rise to correlations, which need to be accounted for in statistical analysis. Mixed modelling provides a flexible framework for this task. The present paper proposes a general method to formulate mixed models for designed experiments with repeated measurements. The approach is exemplified by way of several examples. 相似文献
5.
在我国历史上宗族对农村社区及其居民的生存与发展作用巨大。我国农村几千年“聚族而居”格局是一种文化现象,形成了目前的“差序格局”的农村社会网络,宗族观念根深蒂固,其影响是难以消除的。课题组通过研究认为,必须尊重事实,尊重农村传统文化,正确的认识宗族,反对片面的打压。根据农村“聚族而居”的现状,合理利用和引导宗族,使其在经济、社会和民主发展中发挥积极作用,促进经济发展、社会和谐,促进人性复归。 相似文献
6.
利用荧光原位杂交技术分析新合成异源四倍体拟南芥 总被引：1，自引：0，他引：1
在植物异源倍化育种中或者通过异源多倍化导入有利基因时,初级杂交后代异源多倍体减数分裂期间,避免部分同源染色体干扰,使同源染色体正常联会和配对以及正确分离是产生功能性雌雄配子的细胞学基础。本研究通过种间杂交技术,获得初级杂交后代异源四倍体拟南芥A. suecica,并重点分析其花粉母细胞减数分裂期同源染色体联会和配对情况。利用DAPI技术染色证明了花粉母细胞减数分裂期间核内染色体数目的正确性和均等分裂;而用荧光原位杂交技术进一步证明了核内染色体组的来源的正确性和同源染色体联会和配对的精准性。该结果证实新合成异源多倍体能进行正常的减数分裂和产生功能性雌雄配子,为种属间杂交和异源多倍体育种以及植物杂种优势利用提供了有利的细胞遗传学证据。 相似文献
7.
The phenotypic analysis of field experiments includes information about the experimental design, the randomization structure
and a number of putative dependencies of environment and design factors on the trait investigated. In QTL studies, the genetic
correlation across environments, which arises when the same set of lines is tested in multiple environments, plays an important
role. This paper investigates the effect of model choice on the set and magnitude of detected root QTL in rice. Published
studies on QTLs for root traits indicate that different results are obtained if varying genetic populations are used and also
if different environmental conditions are included. An experiment was conducted with 168 RILs of the Bala × Azucena mapping
population plus parents as checks under four environmental conditions (low light, low nitrogen, drought and a control environment).
We propose a model that incorporates all relevant experimental information into a composite interval mapping approach based
on a mixed model, which especially considers the correlation of genotypes in different environments. An extensive sequential
model selection procedure was applied based on the phenotypic model, using the AIC to determine an appropriate random structure
and Type 3 Wald F-tests for selection of fixed effects. In a first step we checked whether any of the fixed effects and random
(nested) design effects could be dropped. Secondly, an appropriate covariance structure was chosen for genotype × environment
interaction. In a third step Box-Cox transformations were applied based on residual analysis. We compared profiles of composite
interval mapping scans with and without the inclusion of genotype × environment interaction and the experimental design information.
Some distinct differences in profiles indicate that insufficient modeling of the non-QTL part can lead to an overly optimistic
interpretation of QTL main effects in interval mapping. It is concluded that mixed model QTL mapping offers a reasonable way
to separate environmental and genetic influences in the evaluation of quantitative genes and especially enables a more realistic
assessment of QTL and QTL × environment effects than standard approaches by including all relevant effects. 相似文献
8.
为了探讨聚丙烯酰胺对防治北方农牧交错带草场沙化的效果,通过野外小区对比试验和室内分析,采用二因素完全随机设计,研究了在不同植被条件下施用不同剂量聚丙烯酰胺后土壤颗粒组成的变化。结果表明：在30~120kg/hm2的剂量范围内,聚丙烯酰胺能够有效地促进土壤砂粒（2~0.02mm）含量的减少和黏粉粒（<0.02mm）含量的增加,使土壤粗砾化现象得到明显改善。其中尤以30kg/hm2水平的聚丙烯酰胺剂量效果最为明显,砂粒含量的降低幅度比对照提高了6.95~11.29个百分点,黏粉粒含量的增加幅度比对照提高了6.91~12.54个百分点。 相似文献
9.
A population that consisted of F1 half-sibs and their parents was replicated in field plantings to generate roots to identify AFLP molecular markers and compare
statistical models for selection of trait-linked markers using β-carotene content as the grouping variable. Genotypes were
grouped into high and low β-carotene classes based on hierarchical cluster analysis. Association parameters between the high
and low phenotypic classes of β-carotene and molecular marker profiles were made using logistic regression and discriminant
analysis. Logistic regression selected 8 markers less that were associated with β-carotene content compared to discriminant
analysis. Further analysis showed that logistic regression achieved 100% correct classification with the 9 markers selected
compared to 17 markers that were required by discriminant analysis thus making logistic regression more efficient than discriminant
analysis. Logistic regression based on Frequentist hypothesis testing differs from Bayesian based discriminant analysis. This
difference may account for the percent correct classification observed. 相似文献
10.
We presented herein detailed comparison between emulational and real earthquake signals. Intrinsic Mode Functions (IMF) were regarded as products of the empirical mode decomposition (EMD) during Hilbert Huang transform (HHT) processing. This could be ascribed primarily to the failure of separating the correct frequency from mixed and similar frequency components. It was difficult to remove IMF signal from the earthquake record and to obtain correct earthquake energy distribution in frequency. Furthermore, The Hilbert transform sometimes induced erroneous instantaneous frequencies. Thus, care must be taken in the application of HHT in earthquake engineering. The combination of the Hilbert transform with wavelet transform could produce better analysis of earthquake record. 相似文献
11.
City is not a concretionary but a dynamic matter. It should keep close touch with the animated tradition, and we should look forward to its future too. Thus we will be facing with the problem of inheritance and development of the tradition. Because the tradition is a potential for good as wdll as for evil, it can promote the development of a thing, and also may hinder its progress, so there should be correct attitudes to the traditional inheritance. This paper studies the modem application of the traditional street, lane and courtyard, which brings new vitality to the tradition and imparts fresh life to the modem city. 相似文献
12.
Wen Tong Wang Xiaopei 《保鲜与加工》1999,(1):13-17
The punching technology of thin wall pipe with arc shaped end is described.The geometric parameters of the punch are also analyzed by vector analysis method.By minimizing the deformative force,the formula on how to calculate the parameters is derived.The result is proved to be correct by actual experiment. 相似文献
13.
利用等电聚焦聚珍烯酰胺凝电泳方法，分析了大白菜、甘兰、绿菜花、甜椒中８个常用杂交种及其亲本（共２４份材料）的种子水溶蛋白电泳图谱。结果表明，等电聚焦电泳技术分辨率高，电泳条带多而且细，各材料蛋白谱带在２０条左右，信息量大，利于进行深入细致的分析。８个杂交品种（Ｆ１）与其亲本间蛋白电泳图谱都有明显区别，并以此做为检验纯度的依据，进一步建立了这８个杂交种的纯度检验技术，同时在田间进行验证性测定，二者鉴 相似文献
14.
[目的]秋季低温冷害对晚稻生产不利影响极大,准确预警其出现对夺取晩稻高产稳产意义重大。[方法]釆用模糊数学知识原理研制田阳秋季低温冷害始现时段预警输出模型,选配适合于模糊事件秋季低温冷害初日出现时段的隶属函数,计算各预报因子隶属度,结合数理统计学知识,建立多元线性回归预警输出模型,作秋季低温冷害初日出现时段第一次预警；第二次预警,采用模糊数学并、交运算逻辑关系原理制作预警模型。[结果]第一次预警历史拟合率87.3%,第二次预警历史拟合率88.5%。试警四年,第一次试警正确三年,正确率75.0%,二次试警一年,试警正确。[结论]秋季低温冷害模糊数学预警输出模型,技术科学,方法易学易懂,历史正确拟合率、试警准确率结果理想。 相似文献
15.
To analyze and design multivariable control system by modern frequency domain method, there should be a transformation of an arbitrary polynominal matrix into Smith's canonical form. This paper discusses the treating method and technique in programming and gives a N-S flow diagram of program to transform an arbitrary polynominal matrix into Smith's canonical form. Two transformed and applied examples show, that the program is correct, simple, useful and has good suitability. It is applicable to frequency-domain analysis and design of multivariable system. 相似文献
16.
Liao Qing Wen Weibing Ren Zhen 《保鲜与加工》1990,(6):44-48
The method of companion model is applied to the digital simulation of high voltage hybrid AC/DC systems for the first trme in this thesis.The mathematical model of the digital simulation of hybrid AC/DC systems is represented. This method can model the normal states, faults and games of faults of any hybrid AC/DC systems.
The method has a series of advantages : saving the computation and the amounts of memory, high precision and fast calculation and it can be used with convenience.
The simulation results of a hybrid AC/DC system arc in consistent with that of theoretical analysis. It shows that the mathematical model, the simulation method and the program in this thesis are correct. 相似文献
17.
《保鲜与加工》1997,(6):113-115121
In this paper,through the analysis of the engineering quality accident of the top circle beam in a certain big wineshop,a mechanical model of the reinforced concrete circle beam is proposed.By calculation and analysis,the reason of cracking in the circle beam support was found out,and the correct calculated result was made out,so that the engineering quality accident was timety treated. 相似文献
18.
Siti Hazirah Zolkafli Maizura Ithnin Kuang-Lim Chan Mohd Isa Zainol Abidin Ismanizan Ismail Ngoot Chin Ting Leslie Cheng-Li Ooi Rajinder Singh 《Breeding Science》2021,71(2):253
Oil palm is continually being improved via controlled crossing of selected palms to ensure sustainable yields and productivity. As such, correct parental assignment is important as the presence of illegitimates will compromise the progress of improvement. In the present study, we determined the optimal number of microsatellite (SSR) markers for detection of illegitimates in selected oil palm crosses with high confidence. Determining the optimal number of markers to assign parentage will ensure that the DNA fingerprinting will be cost effective for routine use as a quality control tool in oil palm improvement programs. Here, we evaluated a wide range of crosses that included a cross derived from wild germplasm palm. The results revealed that markers with high PIC are informative and detect most of the alleles present in a cross, including those exhibited by the illegitimates. A larger number of optimum sets of markers are needed to detect all illegitimates for crosses with higher levels of genetic diversity. The optimal number of polymorphic SSR markers determined in the present study can ensure that appropriate quality control is implemented for oil palm improvement programs. 相似文献
19.
R. B. Cowley G. J. Ash J. D. I. Harper A. B. Smith B. R. Cullis D. J. Luckett 《Euphytica》2012,186(3):655-669
Phenotyping assays in plant pathology using detached plant parts are multi-phase experimental processes. Such assays involve growing plants in field or controlled-environment trials (Phase 1) and then subjecting a sample removed from each plant to disease assessment, usually under laboratory conditions (Phase 2). Each phase may be subject to non-genetic sources of variation. To be able to separate these sources of variation in both phases from genetic sources of variation requires a multi-phase experiment with an appropriate experimental design and statistical analysis. To achieve this, a separate randomization is required for each phase, with additional replication in Phase 2. In this article, Phomopsis leaf and pod blight (caused by Diaporthe toxica) of Lupinus albus was used as a case study to apply a multi-phase experimental approach to identify genetic resistance to this pathogen, and demonstrate the principles of sound experimental design and analysis in detached plant part assays. In seven experiments, 250 breeding lines, cultivars, landraces, and recombinant in-bred lines from a mapping population of L. albus were screened using detached, inoculated leaves, and/or pods. The experimental, non-genetic variance in Phase 2 varied in magnitude compared to the Phase 1 experimental, non-genetic variance. The reliability of prediction for resistance to Phomopsis pod blight was high (mean of 0.70 in seven experiments), while reliability of prediction for leaf assays was lower (mean 0.35–0.51 depending on the scoring method used). 相似文献
20.
The paper provides a detailed study of switching conditions of minimum-time control systems based on application in engineering. By analysis in theory and experiment, the authors deduce a set of switching conditions with state and control variabes inequality constraints, the variations of system parameters and the time-delay of computer in real time control. As an example, a DC motor speed control system is considered. By digital simulation and physical experiments,these conditions proved to be correct. The method in this paper is also suitable for other control systems using compound control algorithm. 相似文献