共查询到20条相似文献,搜索用时 15 毫秒
1.
Evolutionary or bionic strategies have proven to be powerful tools in many optimisation studies. Starting with some parent generations, producing sets of children, selecting the best children to be new parents yields impressive improvements of the objective when used with some experience and sufficient equipment. During some years of research the parameters of evolutionary optimisation have been investigated. Many successful applications showed where and how to use it. Especially in the case of objective functions with some or many local maxima, evolutionary approaches may propose solutions which gradient based optimisation would hardly find.When used with a large number of optimisation parameters, evolutionary methods seem to be superior to other strategies, as the chances to find good proposals within an acceptable number of trials and within affordable time are much higher.Nevertheless, evolutionary approaches like all optimisation methods require large numbers of studies of individual solutions. The computer power necessary to apply these strategies should not be underestimated. Even with today low cost and high availability of computers, the time to solve problems may be surprisingly long. So all ways of parallel processing, using single computers with many processors or clusters of many computers may speed up the time to do the optimisation.The basic terms of the method are outlined, some problems discussed, some examples given and some proposals made, how to use evolutionary methods in engineering optimisation. Finally some warnings are given trying to prevent potential users from non-realistic expectations. Optimisation is a difficult and consuming process. This holds for evolutionary optimisation as well. 相似文献
2.
J. Subramani 《Biometrical journal. Biometrische Zeitschrift》1992,34(7):843-854
The present paper deals with an alternative and simple procedure to analyse the non-orthogonal data. The procedure is general in nature but has some advantages for the non-orthogonal data due to some missing observations. The procedure is applied to (i) two way classification with unequal number of observations per cell; (ii) randomized block designs with some missing observations and (iii) balanced incomplete block designs and also illustrated with the help of numerical examples. 相似文献
3.
He—Ne激光对家蚕诱变效应的研究 总被引:2,自引:0,他引:2
采用一定剂量的HeNe激光辐照家蚕蛹,在子代与对照相比较,出现熟性、茧形、斑纹等多种变异,利用PAGE,进行血液蛋白质电泳分析结果,也产生谱带数目及活性的变化,首次证明HeNe激光对家蚕具有一定的诱变效应。 相似文献
4.
P. Kaur 《Biometrical journal. Biometrische Zeitschrift》1985,27(7):831-835
For the estimation of finite population variance of a character, DAS and TRIPATHI (1978) proposed some efficient estimators when population mean of variance of some other character (associated with main character) is known. We propose here some estimators for population variance using same information and compare with those given by DAS and TRIPATHI (1978). Some examples are given for illustration. 相似文献
5.
Biotechnological strategies applied to the decontamination of soils polluted with heavy metals 总被引:3,自引:0,他引:3
Soils have been submitted to several contaminants that vary in concentration and composition. Heavy metals can be widely spread and accumulated in those environments due to some inappropriate actions. In this present review some remediation techniques to remediate soils are presented, focusing on the use of plants that are capable of surviving in soils with heavy metals along with the function of some microorganisms in the restoration process. 相似文献
6.
Pulsed field gel electrophoresis of restriction endonuclease digested genomic DNA from a collection of clinical isolates of Rhodococcus equi was used to compare strain diversity on different Thoroughbred horse farms over time. Restricted diversity was found among the isolates tested, as the same strains were detected on multiple farms and in multiple years. Marked variation occurred in strain prevalence with some strains being represented by single isolates, and the most prevalent by 26 isolates. There were dominant strains on some farms and the prevalence of some strains differed between farms. Infection with multiple strains was noted in some cases where multiple isolates from a single foal were examined. 相似文献
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本文主要研究了延迟遗传调控网络的局部稳定性和该网络的Hopf分支存在条件.延迟遗传调控网络是无穷维系统,此类系统在平衡点线性化后的特征方程为超越方程。通过对此超越方程进行研究,得到了系统系数不同时的系统稳定的条件及相关结论,又进一步说明了此系统的Hopf分支存在条件.最后,举一个例子进行了数值仿真验证了所得到的结论. 相似文献
9.
Chemiluminescence (CL) was observed when calcein reacted with potassium ferricyanide. Several metal ions and organic compounds could enhance this CL signal. The possible mechanisms for the CL reactions and the enhancement effect were investigated via studies of the CL kinetic characteristics, the CL spectra of some related reactions, the UV absorption spectra and the fluorescence spectra of some substances. The merits of figures for some substances with CL activity were obtained. A new CL system with calcein as the CL reagent was preliminarily established. 相似文献
10.
J.-P. Vuillez 《Médecine Nucléaire》2009,33(8):465-468
Radioimmunotherapy (RIT) using radiolabeled antibodies is part of internal targeted radiotherapy, which consists in delivering irradiation to tumour cells with a radiopharmaceutical. RIT is increasingly used with some performing clinical results. Here we discuss some aspects of residual disease, which is the best target for RIT, and some recent aspects of radiobiology related to low rate irradiation, which could explain many particular clinical effects of RIT. 相似文献
11.
Colocalization of vasoactive intestinal peptide, neuropeptide Y, calcitonin gene-related peptide, substance P, and tyrosine hydroxylase, respectively, with NADPH-diaphorase staining in rat adrenal gland was investigated using the double labelling technique. All vasoactive intestinal peptide- and some neuropeptide Y-immunoreactive intrinsic neuronal cell bodies seen in the gland were double stained with NADPH-diaphorase. Double labelling also occurred in some nerve fibres immunoreactive to vasoactive intestinal peptide and neuropeptide Y in the medulla and cortex. No colocalization of calcitonin gene-related peptide, substance P or tyrosine hydroxylase immunoreactivity with NADPH-diaphorase staining was observed. However, nerve fibres with varicosities immunoreactive for all the neuropeptides examined were closely associated with some of the NADPH-diaphorase-stained neuronal cell bodies. Thus, in rat adrenal gland, nitric oxide is synthesized in all ganglion cells containing vasoactive intestinal peptide and in some containing neuropeptide Y, but not in those containing calcitonin gene-related peptide, substance P or tyrosine hydroxylase. 相似文献
12.
桃遗传多样性的RAPD分析 总被引:13,自引:1,他引:12
采用RAPD技术,利用200个引物筛选的22个10碱基随机引物对桃182个变种,类型,品种进行DNA扩增。对扩增位点上的带型分析,观察到有的引的在某一位点上明显有带的分离,且S65,S459,S167,S60引物在这一位点可以包含一个类群或几个类群全部的供试品种,变种或类型,但各类群都没有各自独特的特征带。聚类图分析表明,来源无性系的品种遗传一致度最大达0.990;有的品种也表现出较大遗传一致度的为0.985;也有的品种的遗传一致度较低,范围在0.686-0.831之间。对桃的分类,以水蜜桃,寿星桃,垂枝桃作为类群划分较明晰,其它品种的类群划分则较困难,从而也说明了原产中国的桃种质资源的遗传多样性丰富。 相似文献
13.
具有放牧率的某些概周期生态模型 总被引:6,自引:1,他引:5
文[1]研究了具有放牧率的周期生态模型的周期解的存在性、唯一性与稳定性等问题.本文考虑更加广泛的生态模型,即具有放牧率的概周期生态系统的概周期解的存在性、稳定性,通过利用指数型二分性和不动点方法,得到一些新结果. 相似文献
14.
Tjarks W Wang J Chandra S Ji W Zhuo J Lunato AJ Boyer C Li Q Usova EV Eriksson S Morrison GH Cosquer GY 《Nucleosides, nucleotides & nucleic acids》2001,20(4-7):695-698
Several N-3 substituted carboranyl Thd analogs were synthesized. These agents as well as some non-boronated nucleosides were evaluated in phosphoryl transfer assays with recombinant human TK1 and TK2. For some carboranyl thymidine analogs, TK1 phosphorylation rates approached 38% that of thymidine. Their in vitro cytotoxicty appeared to correlate with the TK1 levels in the tested cells. In some cases increased uptake in tumor cell nuclei compared with the surrounding cytoplasm was detected in vitro. 相似文献
15.
Edwin Haslam 《The Biochemical journal》1974,139(1):285-288
The association of some natural and synthetic polyphenols with beta-glucosidase was examined and some observations on the chemical nature of the complex were made. 相似文献
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Advanced research requires intensive interaction among a multitude of actors, often possessing different expertise and usually working at a distance from each other. The field of collaborative research aims to establish suitable models and technologies to properly support these interactions. In this article, we first present the reasons for an interest of Bioinformatics in this context by also suggesting some research domains that could benefit from collaborative research. We then review the principles and some of the most relevant applications of social networking, with a special attention to networks supporting scientific collaboration, by also highlighting some critical issues, such as identification of users and standardization of formats. We then introduce some systems for collaborative document creation, including wiki systems and tools for ontology development, and review some of the most interesting biological wikis. We also review the principles of Collaborative Development Environments for software and show some examples in Bioinformatics. Finally, we present the principles and some examples of Learning Management Systems. In conclusion, we try to devise some of the goals to be achieved in the short term for the exploitation of these technologies. 相似文献
18.
The 23 quaternary and tertiary protoberberines related to berberine were tested for in vitro and/or in vivo fungicidal and herbicidal activities. Among the compounds tested, there was some activity observed with some of only the protoberberinium salts, but not sufficiently strong or broad spectrum for agrochemical use. From the structure-activity point of view, some features can be pointed out. 相似文献
19.
R. M. Preparata E. B. Meyer F. P. Preparata E. M. Simon C. R. Vossbrinck D. L. Nanney 《Journal of molecular evolution》1989,28(5):427-441
Summary We have assembled and analyzed nucleotide sequences for several different rRNA components from tetrahymenine ciliates. These
include previously published and some new 5S and 5.8S rRNAs for a total of 18 species. We also report sequences for some 30
species obtained by primer extension analysis of a region near the 5′ end of the 23S rRNAs (region 580). Phylogenetic trees
have been constructed for these species, utilizing heuristics (shifting ditypic site analysis) described in a companion paper.
The trees based on these sequences are consistent with each other and with those based on longer sequences of the 17S rRNA.
They show the tetrahymenines to consist of a number of distinctive clusters of species. The clusters (ribosets) are homogeneous
with respect to certain life history characteristics, especially the mode of mating type determination, but are inhomogeneous
with respect to some morphological and life history features, such as cyst formation and adaptations to parasitism or carnivory.
Using the same molecular data, we also begin to explore the relationships of the tetrahymenines to some other ciliate taxa
and to some other protists. 相似文献
20.
The female gonad of Platyhelminthes shows a wide variability in its anatomical and cellular organization and submicroscopic
structure, and some characteristics may be useful for elucidating the questioned monophyly of some taxa and reconstructing
the phylogenetic tree of the group. The morphological characters of the female gonad have been subdivided into three levels:
macroscopic, microscopic and ultrastructural, and some examples with potential phylogenetic value are presented for each level.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献