Maximum Similarity Value Research Articles

Marker based Genetic Diversity of Rice Genotypes for Salinity Tolerance at Panicle Initiation Stage

Marker based Genetic Diversity of Rice Genotypes for Salinity Tolerance at Panicle Initiation Stage The study was designed to evaluate salinity tolerance at panicle initiation stage and characterize the genetic diversity in a set of rice genotypes with different adaptation to saline soil using microsatellite markers (SSR markers). In evaluation for salinity tolerance the land races Nona bokra and Pokkali showed high tolerance at 6 EC dsm- 1 (Electrical Conductivity) level. In panicle initiation stage followed by FL 478 and CSR 36 with moderate tolerance. For diversity analysis, a total of 70 SSR primers across the 12 chromosome were used. Of these, 34 were polymorphic among the selected genotypes. The diversity analysis grouped the 13 genotypes into six clusters. Cluster I consisted of three varieties viz., ADT37, ADT 47 and TRY(R)3. Cluster II was the biggest cluster having six varieties viz., ADT42, ADT43, AD09225, FL478, CSR10 and CSR36. Cluster III consisted of mono cluster of TNAU RiceADT49 and Cluster IV consisted of TRY(R)2. Cluster V consisted of monocluster of Pokkali and cluster VI consist of Nonabokra which is highly salt tolerant. The maximum similarity value was 0.828 and the minimum similarity value was 0.502. The genetic distance was ranged between 0.172 to 0.489. The lower genetic distance of 0.172 was observed between FL478 and AD09225, and the higher genetic distance was observed between Nona bokra and ADT47 (0.489) followed by TRY(R)2 and Pokkali. The Polymorphism information content ranged from 0.138 to 0.705. The highest PIC value observed in RM493 (0.705) followed by RM 3412 (0.638) and RM 412(0.591). The lowest PIC value was observed in RM5933 (0.118), RM 240 (0.142) and RM 287 (0.138). Hence parental selection based on the genetic diversity is highly essential to develop a good variety. In future by utilizing the highly genetic divergent parents of ADT(R)47 and Nonabokra may help to develop high yielding salt tolerant varieties.

Numerical taxonomy of <i>Abelmoschus</i> Medik. (Malvaceae) in India

In the present study, numerical taxonomy approach has been used for the first time to access the taxonomy and species relationships of Abelmoschus. Sixteen Abelmoschus taxa were subjected to cluster analysis using 52 diagnostic characters related to root, stem, leaf, flower, fruit and seed. In this analysis, the first six principal components (PCs) accounted for the total variance of 79.22%. Similarity values for all 17 operational taxonomic units (OTUs) ranged from 0.18 to 0.82 with an average of 0.34. Abelmoschus sagittifolius showed maximum similarity value of 0.82 with A. moschatus subsp. tuberosus. On the other hand, minimum similarity values (0.18) were observed between A. tuberculatus and A. moschatus subsp. tuberosus, A. tuberculatus and A. sagittifolius, A. palianus and A. moschatus subsp. tuberosus, and A. palianus and A. sagittifolius. Neighbour joining (NJ) cluster analysis clearly discriminated 17 OTUs into four major clusters. The present study also validates the utility of morphometric analysis of Abelmoschus with respect to the taxonomy and species relationships.Bangladesh J. Plant Taxon. 22(2): 87-98, 2015 (December)

Cautionary tale of using 16S rRNA gene sequence similarity values in identification of human-associated bacterial species.

Modern bacterial taxonomy is based on a polyphasic approach that combines phenotypic and genotypic characteristics, including 16S rRNA sequence similarity. However, the 95 % (for genus) and 98.7 % (for species) sequence similarity thresholds that are currently recommended to classify bacterial isolates were defined by comparison of a limited number of bacterial species, and may not apply to many genera that contain human-associated species. For each of 158 bacterial genera containing human-associated species, we computed pairwise sequence similarities between all species that have names with standing in nomenclature and then analysed the results, considering as abnormal any similarity value lower than 95 % or greater than 98.7 %. Many of the current bacterial species with validly published names do not respect the 95 and 98.7 % thresholds, with 57.1 % of species exhibiting 16S rRNA gene sequence similarity rates ≥98.7 %, and 60.1 % of genera containing species exhibiting a 16S rRNA gene sequence similarity rate <95 %. In only 17 of the 158 genera studied (10.8 %), all species respected the 95 and 98.7 % thresholds. As we need powerful and reliable taxonomical tools, and as potential new tools such as pan-genomics have not yet been fully evaluated for taxonomic purposes, we propose to use as thresholds, genus by genus, the minimum and maximum similarity values observed among species.

A novel method for mineral prospectivity mapping integrating spatial-scene similarity and weights-of-evidence

In this study, a novel method that integrates weights-of-evidence and spatial-scene similarity (WESS) was proposed for mineral prospectivity mapping. The weights-of-evidence model (WofE) was used to rank the importance and determine the weight of each ore-controlled factor. A spatial-scene similarity model was employed as the fundamental kernel theory, utilized to extract the spatial relation between ore-controlled factors and evaluation cells in the spatial-scene, and then used to measure the similarity between two scenes. The spatial-scenes of the known deposits were deemed the mineral cases, and all other spatial scenes were deemed new cases. We performed a similarity computation for each new case and all mineral cases one by one, attached the maximum similarity value to the central evaluation cell of the new case and adopted the value as the cell’s metallogenic potential index. A case study for Fe-Cu-Pb-Zn prospectivity mapping was performed in the Qimantage area of the eastern Kunlun metallogenic belt in China. The WofE and WESS models were used to evaluate the metallogenic potential and the receiver operating characteristic curve (ROC), area under curve (AUC), and a study area cumulative percentage curve (SCP) was utilized to perform a precise evaluation. Our experiment consisted of three sub-experiments (deemed A, B and C). In experiment A, all known deposits were used as training samples and verification samples simultaneously; the evaluation precisions of the WofE and WESS models were 75.8 % and 92.6 %, respectively. In experiment B, two thirds of the known deposits were selected as training samples, and the remaining one third was selected for verification; the evaluation precisions of the WofE and WESS models were 77.8 % and 88.9 %, respectively. In experiment C, half of the known deposits were selected for training, and the other half served as the verification sample; the evaluation precisions of the WofE and WESS models were 66.7 % and 81.6 %, respectively. The results showed that the proposed WESS model was more precise than the traditional WofE model.

Agro-Morpho and Molecular Characterization of World Mini core Collections using Hypervariable Microsatellite Markers in Rice (Oryza sativaL.)

Mini core collection plays an important role in evaluating genetic resources hence, an attempt was made to characterize world mini core collections on the basis of 35 uniformly distributed hyper variable SSR molecular markers. Thirty five markers amplified a total of 131 allelic fragments with an average of 3.28 alleles per locus indicating high level of polymorphism among the analyzed rice lines. The two major clusters shown by PPS SRS technique indicated no difference for grouping japonica and indica genotypes. Therefore the allele specific amplification pattern was adapted for identification of particular genotypes. The similarity coefficients among the genotypes ranged from 0.58 to 0.83 with an average similarity value of 0.36. Maximum similarity value of 88% was observed between PR33319-9-1-1-5-3-5-4-1 and PR-114. Whereas minimum similarity value of 54% was found between TJ 50836 and TJ 35724 followed by TJ 39050 & TJ 35724 and TJ 50836 and NDR359 genotypes with 55% of genetic similarity. Breeders worldwide could use these findings to choice the germplasm for transferring characters

In vitro mutagenesis of Etlingera elatior (Jack) and early detection of mutation using RAPD markers

Mutation breeding techniques in combination with tissue culture and molecular marker methods provide a powerful tool for improvement of vegetatively propagated plants. The aim of this study was to develop a protocol for shoot regeneration and mutation induction of Etlingera elatior. The results of irradiation on in vitro buds of E. elatior showed LD 50 to be 10 Gy, with the survival of explants being sharply reduced at this dosage. All 8 selected gamma irradiated regenerants were differentiated from the untreated control based on the banding patterns obtained using 9 primers, which generated 59 reproducible bands, whereby 35 (55.31%) were found to be polymorphic. Jaccard's coefficient of similarity values ranging from 0.537 to 0.860 were indicative of the level of genetic variation among the mutants studied. For comparison between the potential lines (PL) and the control, a maximum similarity value (0.814) was observed in PL1 mutant, while the minimum value (0.537) was observed in PL7. In summary, a combination of irradiation, regeneration, multiplication, and random amplification of polymorphic DNA (RAPD) analysis for early screening of mutants can speed up the breeding program of E. elatior.

ABS Road Surface Fuzzy Discrimination Based on Normal and Exponential Distribution

The methods of work this identification system is that distill wheel speed characteristics to standard signal then stored in the system. When the first anti-lock loop begin to input the initial velocity to identification model then extract theoretical value of the system and input the actual speed then calculate the similar with theoretical speed. The maximum similarity value is the identification when the pavement is true. After that every cycle identifies monitoring (again identify based on new data) that is establishing state observer. Though it is inaccurate due to various interference identifications or when the adhesion coefficient of pavement has changed ABS will determine quickly make the work more reasonable. Choose normal distribution and exponential distribution of statistical principles to identify the pavement and modify the identification model with gamma membership function. Tire model choose H.B.Pacejka model suitable for programming. It will use Gauss numerical integration and rational interpolation to increase the timeliness of identification. The method this paper described is suitable for the identification of low road.

Halomonas stenophila sp. nov., a halophilic bacterium that produces sulphate exopolysaccharides with biological activity

We have undertaken a polyphasic taxonomic study of two halophilic, Gram-negative bacterial strains, N12(T) and B-100, that produce sulphated exopolysaccharides with biological activity. They were isolated from two different saline soil samples. Both strains grow at NaCl concentrations within the range 3-15 % (w/v) [optimum 5-10 % (w/v)], at 15-37 °C (optimum 20-32 °C) and at pH 6-8 (optimum pH 7-8). Their 16S rRNA gene sequences indicate that they belong to the genus Halomonas in the class Gammaproteobacteria. Their closest relative is Halomonas nitroreducens, to which our strains show maximum 16S rRNA gene sequence similarity values of 98.7 % (N12(T)) and 98.3 % (B-100). Their DNA G+C contents are 61.9 and 63.8 mol%, respectively. The results of DNA-DNA hybridizations showed 43.9 % relatedness between strain N12(T) and H. nitroreducens CECT 7281(T), 30.5 % between N12(T) and Halomonas ventosae CECT 5797(T), 39.2 % between N12(T) and Halomonas fontilapidosi CECT 7341(T), 46.3 % between N12(T) and Halomonas maura CECT 5298(T), 52.9 % between N12(T) and Halomonas saccharevitans LMG 23976(T), 51.3 % between N12(T) and Halomonas koreensis JCM 12237(T) and 100 % between strains N12(T) and B-100. The major fatty acids of strain N12(T) are C(12 : 0) 3-OH (5.42 %), C(15 : 0) iso 2-OH/C(16 : 1)ω7c (17.37 %), C(16 : 0) (21.62 %) and C(18 : 1)ω7c (49.19 %). The proposed name for the novel species is Halomonas stenophila sp. nov. Strain N12(T) ( = CECT 7744(T) = LMG 25812(T)) is the type strain.

Extraction of neurons from images of mouse brain slices based on automated selection of connected morphological filters

We describe the results of a study on creating an algorithm for automated selection of connected morphological filters to solve image segmentation problems. We propose a similarity measure for image partition. It is used to select the best filters from given families of connected morphological filters in such a way that partition obtained by applying the watershed-segmentation algorithm to a filtered image has the maximum similarity value with the given partition. This method is used to extract neurons from images of mouse brain slices. Experimental research has confirmed that this method is applicable for automated processing and analysis of slice images.

Assessment of genetic diversity among collected genotypes of Chlorophytum borivilianum using random amplified polymorphic DNA (RAPD) markers

Chlorophytum borivilianum (Family: Liliaceae), an important threatened medicinal herb is designated as ‘Rare’ in Red Data Book of Indian plants. Morphological as well as biochemical markers used in the authentication of herbal drugs have many limitations due to the impact of environmental conditions. Molecular markers therefore, are an important tool in quality assurance and preservation of germplasm of medicinal plant species in the plant kingdom. In this study, RAPD markers were used to assess genetic diversity in nine genotypes of C. borivilianum collected from different geographical regions of Chhattisgarh, Madhya Pradesh and Uttar Pradesh. Out of the 43 bands obtained, 26 were polymorphic, with (67.49) percent polymorphism, thus, revealing a high degree of polymorphism. Percentage of polymorphism detected with each primer was as high as 80.00 (OP L18) and as low as 33.30 (OP L12). The Jaccard’s similarity coefficient ranged from 0.609 to 0.810. The maximum similarity value was noticed between V 3 and V 5 genotypes collected from Lamni (C.G.) and Chitrakoot (U.P.), respectively. Keywords : Genetic diversity, random amplified polymorphic DNA (RAPD)-PCR, UPGMA, Chlorophytum borivilianum.

Structure and Diversity of Arsenic Resistant Bacteria in an Old Tin Mine Area of Thailand

The microbial community structure in Thailand soils contaminated with low and high levels of arsenic was determined by denaturing gradient gel electrophoresis (DGGE). Band pattern analysis indicated that the bacterial community was not significantly different in the two soils. Phylogenetic analysis obtained by excising and sequencing six bands indicated that the soils were dominated by Arthobacter koreensis and proteobacteria. Two hundred and sixty-two bacterial isolates were obtained from arsenic contaminated soils. The majority of the As resistant isolates were gram-negative bacteria. MIC studies indicated that all of the tested bacteria had greater resistance to arsenate than arsenite. Some strains were capable of growing in medium containing up to 1,500 mg/l arsenite and arsenate. Correlations analysis of resistance patterns of arsenite resistance indicated that the isolated bacteria could be categorized into 13 groups, with a maximum similarity value of 100%. All strains were also evaluated for resistance to eight antibiotics. The antibiotic resistance patterns divided the strains into 100 unique groups, indicating that the strains were very diverse. Isolates from each antibiotic resistance group were characterized in more detail by using the repetitive extragenic palindromic-PCR (rep-PCR) DNA fingerprinting technique with ERIC primers. PCR products were analyzed by agarose gel electrophoresis. The genetic relatedness of 100 bacterial fingerprints, determined by using Pearson product moment similarity coefficient, showed that the isolates could be divided into four clusters, with similarity values ranging from 5-99%. While many isolates were genetically diverse, others were clonal in nature Additionally, the arsenic-resistant isolates were examined for the presence of arsenic resistance (ars) genes by using PCR, and 30% of the isolates were found to carry an arsenate reductase encoded by the arsC gene.

Molecular and Phenotypic Evaluation of Lichtheimia corymbifera (Formerly Absidia corymbifera ) Complex Isolates Associated with Human Mucormycosis: Rehabilitation of L. ramosa

Thirty-eight isolates (including 28 isolates from patients) morphologically identified as Lichtheimia corymbifera (formerly Absidia corymbifera) were studied by sequence analysis (analysis of the internal transcribed spacer [ITS] region of the ribosomal DNA, the D1-D2 region of 28S, and a portion of the elongation factor 1alpha [EF-1alpha] gene). Phenotypic characteristics, including morphology, antifungal susceptibility, and carbohydrate assimilation, were also determined. Analysis of the three loci uncovered two well-delimited clades. The maximum sequence similarity values between isolates from both clades were 66, 95, and 93% for the ITS, 28S, and EF-1alpha loci, respectively, with differences in the lengths of the ITS sequences being detected (763 to 770 bp for isolates of clade 1 versus 841 to 865 bp for isolates of clade 2). Morphologically, the shapes and the sizes of the sporangiospores were significantly different among the isolates from both clades. On the basis of the molecular and morphological data, we considered isolates of clade 2 to belong to a different species named Lichtheimia ramosa because reference strains CBS 269.65 and CBS 270.65 (which initially belonged to Absidia ramosa) clustered within this clade. As neotype A. corymbifera strain CBS 429.75 belongs to clade 1, the name L. corymbifera was conserved for clade 1 isolates. Of note, the amphotericin B MICs were significantly lower for L. ramosa than for L. corymbifera (P < 0.005) but were always <or=0.5 microg/ml for both species. Among the isolates tested, the assimilation of melezitose was positive for 67% of the L. ramosa isolates and negative for all L. corymbifera isolates. In conclusion, this study reveals that two Lichtheimia species are commonly associated with mucormycosis in humans.

Genetic Similarity of Lilium brownii var. colchesteri in Japan and Korea

Genetic similarity of Lilium brownii var. colchesteri cultivated in Japan and Korea was investigated with 302 AFLP markers. Average, maximum and minimum genetic similarity value within the whole accessions of Japan and Korea was 0.9788, whereas those between them and one Chinese accession was 0.9477. The threshold similarity value for identification of clones was estimated to be 0.97 by the same method with 10 clonally propagated individuals of L. longiflorum ‘Hinomoto’ and referring previous reports. 90.2% of pairs within the whole accessions of Japan and Korea represented higher the values than the threshold. Excluding five individuals, 98.9% of pairs showed higher the values. The individuals of L. brownii var. colchesteri in Japan and Korea, therefore, are considered to be almost one clone, and the introduction of the lily into Japan seems to have been through Korean Peninsula.

Characterization of Colletotrichum lindemuthianum Isolates from the State of Minas Gerais, Brazil

AbstractAnthracnose disease of common bean (Phaseolus vulgaris), caused by Colletotrichum lindemuthianum, is responsible for extensive yield losses worldwide. This pathogen is known to vary greatly in its pathogenicity. Control strategies include chemical control and, mainly, the development of resistant cultivars, taking into account the population structure of C. lindemuthianum. The objective of this study was to investigate the pathogenic and genetic diversity and population structure among C. lindemuthianum isolates collected in Minas Gerais state, Brazil. When these isolates were inoculated on 12 differential cultivars, a total of 10 races were identified within a series of 48 isolates collected in Minas Gerais, Brazil. Races 65, 81 and 73 were the most frequent races and occurred in most of the regions. This study also detected race 337, which had not been reported previously in the literature. Random amplified polymorphic DNA (RAPD) analysis performed on the same 48 isolates revealed great genetic diversity, clustering the series into five groups at a maximum similarity value of 89.6%. There was no clear relationship between the loci sampled by RAPD markers and the pathogenic characterization. Analysis of molecular variance showed that 96.06% of the variability was contained within regions and 3.94% among regions, indicating a high exchange of genetic material among the regions of the State. Most of the variability was detected within races (75.24%). The pathogenicity and RAPD assays corroborated the broad genetic diversity of the pathogen and the results have been useful in breeding for resistance to anthracnose.

Improved Strategy for Comparing Microbial Assemblage Fingerprints

Microbial fingerprinting techniques permit the rapid visualization of entire assemblages in single assays, allowing direct comparison of communities in different samples, where the null hypothesis of such analyses is that all samples are the same. The comparison of fingerprints relies upon the precise estimation of all amplified DNA fragment lengths, which correspond to operational taxonomic units (OTU; analogous, but not equal to, a taxon in macroorganism studies). However, computer interpolation of size standards (and consequently OTU size calling) can be imprecise between gel runs, which can lead to imprecise calculation of similarity indices between multiple assemblages. To account for OTU size calling imprecision, all fragments within a range of sizes (a window) can be combined (i.e., "binned") where the window is as wide as the imprecision of OTU size calling. However, artifacts may occur upon binning samples that may cause samples to appear less similar to each other, caused by splitting of OTU between adjacent bin windows. In this work we present an improved binning technique that accounts for OTU size calling imprecision in the comparison of multiple fingerprints. This technique comprises binning all pairwise comparisons in multiple bin window frames, where the starting size of the window (i.e., frame) is shifted by +1 bp for a total of x frames, where x bp is the width of the maximum bin window size in any binning scheme. Pairwise similarity indices between different community fingerprints are calculated for each of the x frames. To best address the null hypothesis of the community comparison, the maximum similarity value of all x frames is then used in downstream analyses to compare the communities. We believe this binning technique provides the most accurate and least biased comparison between different microbial fingerprints.

Bacillus axarquiensis sp. nov. and Bacillus malacitensis sp. nov., isolated from river-mouth sediments in southern Spain

Two Gram-positive, rod-shaped, endospore-forming bacteria (strains CR-119(T) and CR-95(T)) were isolated from brackish sediments in the mouth of the river Velez in Malaga, southern Spain, and subjected to a polyphasic taxonomic study. Phenotypic tests showed that these strains were related to other Bacillus species at a similarity level of less than 87.6 %. Both strains are halotolerant, aerobic, chemoheterotrophic, motile with peritrichous flagella and biosurfactant producers. Their endospores are oval, subterminal and non-deforming structures. The predominant menaquinone in both strains is MK-7. The fatty-acid profiles of both strains contain large quantities of branched and saturated fatty acids. The major fatty acids (%) are 15 : 0 anteiso (32.4), 15 : 0 iso (16.8), 17 : 0 iso (13.4), 16 : 0 (11.5) and 17 : 0 anteiso (10.2) in strain CR-119(T) and 15 : 0 anteiso (37.5), 17 : 0 iso (16.0) and 17 : 0 anteiso (15.8) in strain CR-95(T). The G + C contents of strains CR-119(T) and CR-95(T) are 41.0 and 42.5 mol%, respectively. RAPD analysis confirmed the low degree of similarity between the two strains and also amongst other Bacillus species. 16S rRNA gene analysis of strain CR-119(T) showed the highest sequence similarity to be 97.4 %, with Bacillus mojavensis and Bacillus subtilis subsp. spizizenii. In the case of strain CR-95(T), the maximum similarity value was 99.5 %, with B. mojavensis. DNA-DNA hybridization of strains CR-119(T) and CR-95(T) with the above species produced values lower than 46.9 %. Therefore, on the basis of phenotypic characteristics, phylogenetic data and genomic distinctiveness, we conclude that these Bacillus strains merit classification as novel species, for which we propose the names Bacillus axarquiensis sp. nov. (type strain CR-119(T) = CECT 5688(T) = LMG 22476(T)) and Bacillus malacitensis sp. nov. (type strain CR-95(T) = CECT 5687(T) = LMG 22477(T)).

Molecular Variability of Mycosphaerella graminicola as Detected by RAPD Markers

AbstractA total of 90 isolates of Mycosphaerella graminicola, the cause of septoria tritici leaf blotch of wheat, were tested for DNA polymorphism using 15 decamer random primers. There was a high level of genetic variability among isolates. In 131 random amplified polymorphic DNA (RAPD) fragments, which were produced, 96% were polymorphic. Based on multilocus analysis, 40 different molecular phenotypes were detected. These molecular phenotypes were randomly distributed among sampling sites, suggesting that no clonal structure existed in the population. Cluster analysis showed that the maximum similarity value among isolates was approximately 81% and no identical isolates were detected, indicating that every isolate was a unique genotype. The high degree of DNA polymorphism, the large number of different molecular phenotypes, their random distribution and the results of the cluster analysis all suggested that sexual reproduction has a major role in the genetic structure of M. graminicola in western Canada. The presence of sexual reproduction provides the opportunity for development of new virulent genotypes in the population and suggests that the pathogen may adapt rapidly to any race‐specific sources of resistance. Therefore, when breeding for resistance to M. graminicola, emphasis should be placed on use of non‐race‐specific resistance.

DNA base composition heterogeneity in some agarophytes (Gracilariales, Rhodophyta) from Mexico and the Philippines

Estimates of nuclear DNA base composition by determination of thermal denaturation temperatures (Tm) indicate guanine + cytosine (G + C) levels of 35.4–46.8% for ten species of the Gracilariaceae, representing the generaGracilaria andHydropuntia. Tm values were found to be reproducible with variation among most samples and replicates of less than 1 °C and 2 mol%. Interspecific variation in G + C values was less than 11.4% amongGracilaria species. Calculation of intragenomic base pair composition distribution based on mid-resolution thermal denaturation (ΔA 1 °C/min with 4s interval ΔH and dT logging) indicated an inverse relationship between maximum similarity values and taxonomic rank. Intraspecific (population level) maximum similarity (homology) values were estimated to range from 79–90% inGracilaria tikvahiae (4 isolates). Interspecific values of 46–69% were found in 13 species ofGracilaria. Nucleotide distribution similarity values for the Gracilariaceae are compared with previous information for genome organization and complexity, genome size and karyotype patterns.

Symbolic clustering using a new similarity measure

A hierarchical, agglomerative, symbolic clustering methodology based on a similarity measure that takes into consideration the position, span, and content of symbolic objects is proposed. The similarity measure used is of a new type in the sense that it is not just another aspect of dissimilarity. The clustering methodology forms composite symbolic objects using a Cartesian join operator when two symbolic objects are merged. The maximum and minimum similarity values at various merging levels permit the determination of the number of clusters in the data set. The composite symbolic objects representing different clusters give a description of the resulting classes and lead to knowledge acquisition. The algorithm is capable of discerning clusters in data sets made up of numeric as well as symbolic objects consisting of different types and combinations of qualitative and quantitative feature values. In particular, the algorithm is applied to fat-oil and microcomputer data.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

A learning word-spotting method for speaker-independent word recognition in noisy environments

A learning word-spotting method has been proposed for the purpose of robust speaker-independent word recognition in noisy environments. In order to avoid word boundary detection errors at the recognition stage, the method employs word spotting based on the multiple similarity method, which was shown to be effective for noisy speech data. The learning process uses synthesized noisy speech data, a mixture of pure speech data and noise data, to design reliable word reference vectors for the word spotting. Word feature vectors with maximum multiple similarity values are automatically extracted by the word spotting. During the learning process, the signal-to-noise ratio (SNR) of the synthesized data is gradually decreased to perform word spotting accurately. Experiments were carried out for 13 words, including ten Japanese digits, spoken by 50 males. Under the condition of 10 dB, SNR contaminated by concourse noise, the recognition scores of 85.5 % and 94.1% were obtained by word spotting, without learning and with learning, respectively. The results have shown the effectiveness of the proposed method in noisy environments.