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1.
Yihe Lu Bojie Fu Liding Chen Zhiyun Ouyang Jianying Xu 《Biodiversity and Conservation》2006,15(8):2813-2827
Resolving the conflicts between biodiversity conservation and socioeconomic development is a global pursuit for the long-run
prospects of the human species. Based on Wenchuan County, a typical county in southwestern China, a group of 20 indicators
quantifying regional biodiversity and socioeconomic development was established to classify and evaluate the county area spatially.
A fuzzy c-means clustering (FCM) algorithm was used as the classification method. Three indices including BD, DL and DR characterizing
the value of biodiversity, the level and rate of socioeconomic development of the delineated regions were formulated. The
results indicated that Wenchuan County was optimally classified into 4 types of regions (region I to IV). The area percentages
of the regions vary widely from 4.3 to 65.7%. The sequences of the regions on biodiversity, socioeconomic development level,
and socioeconomic development rate were, respectively, IV > II > III > I, I > III > II > IV and III >I >II >IV. The spatial
strategy on coordinating biodiversity conservation and regional development is to develop mainly from the east(I, II, III)
and to conserve mainly in the west(IV). Eco-industry, such as eco-tourism and eco-agriculture, need to be emphasized in the
process of regional development. The quantitative methods used here may have a wide applicability. 相似文献
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ANTHONY V. HALL F.L.S. 《Biological journal of the Linnean Society. Linnean Society of London》1991,42(4):425-456
A unifying theory for systematic analysis states that a number of methods should be used jointly to cope with various kinds of data; also that groups should be as consistent as possible, be made with least information loss, and where needed, be polythetic. A test of relationship, homogeneity, can use various kinds of data. It can take account of the internal variation of aggregate items such as genera. It can give due emphasis to smaller clusters that have likely important contexts of external items. It helps in analysing trends, cores and hazes in dendrograms. A proposed detector for formal groups can be based on measures of isolation, identifiability and inclusiveness. Non-mathematical, inter-item reaction tests such as hybridization and serology can also be used in grouping. All relationship data are used polythetically to reveal natural groups. This leads to a unified informational concept for taxa. This is more useful than the biological species concept that is restricted to inter-breeding data. All the methods appear to be analogues of the powerful human grouping instinct. The resulting compatibility is important as precise methods are needed mainly when the data are too complex for the mind to use reliably. Cladograms can be made by self-graded deweighting of homogeneity and agglomerative clustering. Unlike classical cladistics this can reveal any polythetic group. Finding the derived states for making cladograms is often much too hypothetical for a fully cladistic approach to be properly precise. Instead, where the evidence is weak, a milder strength of graded deweighting is used for the cladistic properties, which help to show relationships along with the others. Axiomatic failures of other classes of grouping methods are discussed. Unavoidable remnants of instinctive processing lower the precision of all the methods. The Uniter computer program, based on the theory, is tested with finely graded values of artificially ‘evolved’ items and with coarsely coded cladistic data. The results show that with natural data, the program should act as a fairly sensitive probe of past evolutionary branching. Another test shows how specimens from species complexes can be grouped and how distinctions between groups are analysed. 相似文献
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L. P. Lefkovitch 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1985,70(6):585-589
Summary Significant genotype-environment interactions in an ANOVA can be found for a number of reasons: one is the differences in
the among-environments variances for each genotype, another is the differences in the ordering of the environments by each
genotype. Using conditional clustering, groups may be formed in which the means, variances and patterns are used simultaneously
but separately to decide on group homogeneity.
Contribution No. I-685 from the Engineering and Statistical Research Institute 相似文献
8.
A new dissimilarity measure, Uppsala dissimilarity, is proposed. It is a Manhattan-type measure in between the Canberra and Gower measures, based on the differences between scores in relevés compared, but it also takes both the sums of scores and the difference between maximum and minimum score into account. The measure is considered realistic for phytosociological material.A new optimality criterion has been developed after unsatisfactory results had been obtained with the DOL criterion (Popma et al. 1983) which was developed previously by our group. Problems with DOL were especially met when the criterion was applied to the distribution of only one species over the cluster array obtained. The new criterion takes both internal cluster homogeneity and between-cluster dissimilarity into account. Between-cluster dissimilarity is calculated for all other clusters and not only for the nearest neighbour, as in DOL. The new criterion has both an unweighted form: SOM, and a form with weighting for cluster size: SWOM.This new criterion was successfully applied to the evaluation of the sharpness of distribution of individual species over cluster arrays, under the name of SIM: species indication measure and SWIM, species weighted indication measure.The measures were applied to some test data. Differences between the unweighted and weighted forms were found which could not be easily interpreted.Some remarks are made on the coherence of d-SAHN and h-SAHN approaches in agglomerative clustering within the new strategy proposed.Abbreviations DOL =
Detection of Optimal Level
- S(W)IM =
Species (Weighted) Indication Measure
- S(W)OM =
Standardized (Weighted) Optimality Measure
- UD =
Uppsala Dissimilarity measure
- WPGMA =
Weighted Pair-Group Method Average linking clustering
- SAHN =
Sequential Agglomerative Hierarchical Non-overlapping clustering 相似文献
9.
A procedure for monitoring plant community change was described using data from 189 quadrats (each 0.09 m2 in area) from or near 11 Carex exserta meadow sites in the high Sierra Nevada, California, USA. Initially the quadrats were agglomerated into five clusters by the flexible clustering strategy (beta=–0.25) with the standard absolute distance resemblance function. Data for each quadrat were cover percentages for C. exserta, other plants, litter, soil, gravel, and rock. The five clusters appeared to define a cover gradient, from quadrats with mostly gravel and rock to those with mostly C. exserta, and were accordingly designated pioneer, low seral, mid-seral, high seral, and climax.Classification functions (from discriminant analysis) are used with values of the variables to classify individual quadrats on sites used to monitor change. A site is characterized at repeated observations by the proportions of quadrats in each class. Within-class (low seral vs. low seral) rather than between-class (pioneer vs. low seral) tests are made for presence of change. Confidence intervals for differences in proportions of quadrats or individual quadrat probabilities of class membership are computed. If the confidence intervals do not cover zero, values for time one versus time two differ significantly. 相似文献
10.
Summary The batch fermentation of whey permeate to lactic acid was improved markedly by the addition of enzymehydrolyzed whey protein. Acid concentrations greater than 90 g/l were achieved at a productivity of 4.3 g/l per h and a 98% substrate use. Cell mass concentration reached 6 g/l. The acid productivity achieved is somewhat higher than that typical for fermentation of whole whey. The process economics, based on in-house hydrolyzate preparation, look promising. Presented in this paper are the experimental results showing the effects of hydrolyzate concentration on acid and cell mass production. 相似文献