• Title/Summary/Keyword: Similarity matrices

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Classification of Mental States Based on Spatiospectral Patterns of Brain Electrical Activity

  • Hwang, Han-Jeong;Lim, Jeong-Hwan;Im, Chang-Hwan
    • Journal of Biomedical Engineering Research
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    • v.33 no.1
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    • pp.15-24
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    • 2012
  • Classification of human thought is an emerging research field that may allow us to understand human brain functions and further develop advanced brain-computer interface (BCI) systems. In the present study, we introduce a new approach to classify various mental states from noninvasive electrophysiological recordings of human brain activity. We utilized the full spatial and spectral information contained in the electroencephalography (EEG) signals recorded while a subject is performing a specific mental task. For this, the EEG data were converted into a 2D spatiospectral pattern map, of which each element was filled with 1, 0, and -1 reflecting the degrees of event-related synchronization (ERS) and event-related desynchronization (ERD). We evaluated the similarity between a current (input) 2D pattern map and the template pattern maps (database), by taking the inner-product of pattern matrices. Then, the current 2D pattern map was assigned to a class that demonstrated the highest similarity value. For the verification of our approach, eight participants took part in the present study; their EEG data were recorded while they performed four different cognitive imagery tasks. Consistent ERS/ERD patterns were observed more frequently between trials in the same class than those in different classes, indicating that these spatiospectral pattern maps could be used to classify different mental states. The classification accuracy was evaluated for each participant from both the proposed approach and a conventional mental state classification method based on the inter-hemispheric spectral power asymmetry, using the leave-one-out cross-validation (LOOCV). An average accuracy of 68.13% (${\pm}9.64%$) was attained for the proposed method; whereas an average accuracy of 57% (${\pm}5.68%$) was attained for the conventional method (significance was assessed by the one-tail paired $t$-test, $p$ < 0.01), showing that the proposed simple classification approach might be one of the promising methods in discriminating various mental states.

A Study on the Musical Theme Clustering for Searching Note Sequences (음렬 탐색을 위한 주제소절 자동분류에 관한 연구)

  • 심지영;김태수
    • Journal of the Korean Society for information Management
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    • v.19 no.3
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    • pp.5-30
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    • 2002
  • In this paper, classification feature is selected with focus of musical content, note sequences pattern, and measures similarity between note sequences followed by constructing clusters by similar note sequences, which is easier for users to search by showing the similar note sequences with the search result in the CBMR system. Experimental document was $\ulcorner$A Dictionary of Musical Themes$\lrcorner$, the index of theme bar focused on classical music and obtained kern-type file. Humdrum Toolkit version 1.0 was used as note sequences treat tool. The hierarchical clustering method is by stages focused on four-type similarity matrices by whether the note sequences segmentation or not and where the starting point is. For the measurement of the result, WACS standard is used in the case of being manual classification and in the case of the note sequences starling from any point in the note sequences, there is used common feature pattern distribution in the cluster obtained from the clustering result. According to the result, clustering with segmented feature unconnected with the starting point Is higher with distinct difference compared with clustering with non-segmented feature.

Determining the Size of a Hankel Matrix in Subspace System Identification for Estimating the Stiffness Matrix and Flexural Rigidities of a Shear Building (전단빌딩의 강성행렬 및 부재의 강성추정을 위한 부분공간 시스템 확인기법에서의 행켈행렬의 크기 결정)

  • Park, Seung-Keun;Park, Hyun Woo
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.26 no.2
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    • pp.99-112
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    • 2013
  • This paper presents a subspace system identification for estimating the stiffness matrix and flexural rigidities of a shear building. System matrices are estimated by LQ decomposition and singular value decomposition from an input-output Hankel matrix. The estimated system matrices are converted into a real coordinate through similarity transformation, and the stiffness matrix is estimated from the system matrices. The accuracy and the stability of an estimated stiffness matrix depend on the size of the associated Hankel matrix. The estimation error curve of the stiffness matrix is obtained with respect to the size of a Hankel matrix using a prior finite element model of a shear building. The sizes of the Hankel matrix, which are consistent with a target accuracy level, are chosen through this curve. Among these candidate sizes of the Hankel matrix, more proper one can be determined considering the computational cost of subspace identification. The stiffness matrix and flexural rigidities are estimated using the Hankel matrix with the candidate sizes. The validity of the proposed method is demonstrated through the numerical example of a five-story shear building model with and without damage.

Proposing Shape Alignment for an Improved Active Shape Model (ASM의 성능향상을 위한 형태 정렬 방식 제안)

  • Hahn, Hee-Il
    • Journal of Korea Multimedia Society
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    • v.15 no.1
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    • pp.63-70
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    • 2012
  • In this paper an extension to an original active shape model(ASM) for facial feature extraction is presented. The original ASM suffers from poor shape alignment by aligning the shape model to a new instant of the object in a given image using a simple similarity transformation. It exploits only informations such as scale, rotation and shift in horizontal and vertical directions, which does not cope effectively with the complex pose variation. To solve the problem, new shape alignment with 6 degrees of freedom is derived, which corresponds to an affine transformation. Another extension is to speed up the calculation of the Mahalanobis distance for 2-D profiles by trimming the profile covariance matrices. Extensive experiment is conducted with several images of varying poses to check the performance of the proposed method to segment the human faces.

Content-based Image Retrieval System (내용기반 영상검색 시스템)

  • Yoo, Hun-Woo;Jang, Dong-Sik;Jung, She-Hwan;Park, Jin-Hyung;Song, Kwang-Seop
    • Journal of Korean Institute of Industrial Engineers
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    • v.26 no.4
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    • pp.363-375
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    • 2000
  • In this paper we propose a content-based image retrieval method that can search large image databases efficiently by color, texture, and shape content. Quantized RGB histograms and the dominant triple (hue, saturation, and value), which are extracted from quantized HSV joint histogram in the local image region, are used for representing global/local color information in the image. Entropy and maximum entry from co-occurrence matrices are used for texture information and edge angle histogram is used for representing shape information. Relevance feedback approach, which has coupled proposed features, is used for obtaining better retrieval accuracy. Simulation results illustrate the above method provides 77.5 percent precision rate without relevance feedback and increased precision rate using relevance feedback for overall queries. We also present a new indexing method that supports fast retrieval in large image databases. Tree structures constructed by k-means algorithm, along with the idea of triangle inequality, eliminate candidate images for similarity calculation between query image and each database image. We find that the proposed method reduces calculation up to average 92.9 percent of the images from direct comparison.

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Evaluation of ISSR and RAPD Markers for the Detection of Genetic Diversity in Mulberry (Morus spp.)

  • Venkateswarlu, M.;Nath, B.Surendra;Saratchandra, B.;Urs, S.Raje
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.2
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    • pp.207-215
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    • 2004
  • The present study was carried out to evaluate the ISSR and RAPD markers for their efficiency as genetic marker systems to establish the relationships between 18 mulberry genotypes. A total of 36 from 56 (64%) RAPD primers and 12 from 48 (25%) ISSR primers produced reproducible amplification patterns. A high proportion of polymorphic bands ranging from 44 to 91% was observed respectively with RAPD and ISSR markers. The average Resolving Power (Rp) of ISSR primers was higher than RAPD primers. The ISSR primers, UBC 825, 868 and 873, and RAPD primers, UBC 712, 720 and 729, possessed the highest Rp values and could in each instance distinguish all the 18 genotypes. Similarity matrix values were estimated based on Jaccards coefficient, considering 109 polymorphic ISSR and 212 polymorphic RAPD bands and two dendrograms were constructed. The dendrograms obtained with ISSR and RAPD markers distinguished the eight exotic genotypes from the ten indigenous (Indian) genotypes. A significant correlation value (r=0.959; p=0.001) for the cophenetic matrix between the RAPD and ISSR matrices was observed. The results indicated that the ISSR and RAPD markers could assist in the differentiation of genotypes and permit the determination of genetic distances that might be exploited by mulberry breeders in improvement programs.

Genetic Variations within and between Blue Crab (Portunus trituberculatus) Groups

  • Song, Young-Jae;Yoon, Jong-Man
    • Development and Reproduction
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    • v.25 no.3
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    • pp.185-192
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    • 2021
  • The five oligonucleotide primers (oligo-primers) turned out a total of 335 fragments (FMs) (52.9%) in the blue crab (Portunus trituberculatus) group alpha and 298 FMs (47.1%) in the crab group beta, with the FM scales range varying from 100 bp to 2,000 bp. The highest band-sharing (BS) value (0.907) was found between individual's no. 19 and no. 20 within the blue crab group beta. Parties in the blue crab group beta (0.601±0.017) had higher BS rates than did parties from the crab group alpha (0.563±0.017) (p<0.05). The polar dendrogram got by the five oligo-primers points out two genetic extents: bundle I (BLUECRAB 01, 03, 04, 05, 06, 08, and 10) and bundle II (BLUECRAB 02, 07, 09. 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, and 22). The OPD-01 primer revealed 22 loci shared by all the examples of the as FMs of 1,000 bp. The oligo-primer OPA-05 made unique loci shared to each group (ULSEG), almost 400 bp and 500 bp, individually, in blue crab group beta. The remaining oligo-primers did not reveal any loci shared by the two crab groups (LSTG). The average number of ULSEG was diverse and 1.6-fold higher in the crab group beta than in the crab group alpha.

Genetic Distances of Three Mollusk Species Investigated by PCR Analysis

  • Oh, Hyun;Yoon, Jong-Man
    • Development and Reproduction
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    • v.18 no.1
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    • pp.43-49
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    • 2014
  • Three species of Nortamea concinua (NC) and Haliotis discus hannai (HDH) from Tongyeong and Sulculus diversicolor supertexta (SDS) are widely distributed on the coast of the Yellow Sea, southern sea and Jeju Island in the Korean Peninsula under the innate ecosystem. There is a need to understand the genetic traits and composition of three mollusk species in order to evaluate exactly the patent genetic effect. PCR analysis was performed on DNA samples extracted from a total of 21 individuals using seven decamer oligonucleotides primers. Seven primers were shown to generate the unique shared loci to each species and shared loci by the three species which could be clearly scored. A hierarchical clustering tree was constructed using similarity matrices to generate a dendrogram, which was facilitated by the Systat version 10. 236 specific loci, with an average of 56.3 per primer, were identified in the NC species. 142 specific loci, with an average of 44.7 per primer, were identified in the HDH species. Especially, 126 numbers of shared loci by the three species, with an average of 18 per primer, were observed among the three species. Especially, the decamer primer BION-75 generated 7 unique loci to each species, which were identifying each species, in 700 bp NC species. Interestingly, the primer BION-50detected 42 shared loci by the three species, major and/or minor fragments of sizes 100 bp and 150 bp, respectively, which were identical in all samples. As regards average bandsharing value (BS) results, individuals from HDH species (0.772) exhibited higher bandsharing values than did individuals from NC species (0.655). In this study, the dendrogram obtained by the seven decamer primers indicates three genetic clusters: cluster 1 (CONCINNA 01~CONCINNA 07), cluster 2 (HANNAI 08~HANNAI 14), cluster 3 (SUPERTEXTA 15~SUPERTEXTA 21). Comparatively, individuals of HDH species were fairly closely related to that of SDS species, as shown in the hierarchical dendrogram of genetic distances.

Analysis of Diversity of Panax ginseng Collected in Korea by RAPD Technique (RAPD 방법을 이용한 국내 수집 인삼 (Panax ginseng C. A. Meyer)의 다양성 분석)

  • Seo, Sang-Deog;Yuk, Jin-Ah;Cha, Sun-Kyung;Kim, Hyun-Ho;Seong, Bong-Jae;Kim, Sun-Ick;Choi, Jae-Eul
    • Korean Journal of Medicinal Crop Science
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    • v.11 no.5
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    • pp.377-384
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    • 2003
  • Genetic differences among nine land races of Korean ginseng (Panax ginseng C. A. Meyer) were examined using RAPD markers. Land races of Korean ginseng were collected from nine regions in Korea: Cheongwon, Guesan, Geumsan, Namwon, Pochun, Yangju, Yeoncheon, Yeongju. Out of 48 RAPD primers tested, 5 primers (OPA 7, OPA 13, URP 2, URP 3 and UBC 3) produced remarkable bands which showing polymorphisms among evaluated collections. Lower levels of genetic diversity were in detected same land races than among other land races. Genetic differences within and among land races indicate heterogeneity. These results indicate that cultivated ginseng in Korea is heterogeneous. Genetic similarity matrices of RAPD profiles were generated via coefficients of variation and the data were processed by the cluster analysis (UPGMA). When 90 collections were evaluated using selected 5 primers, those were clustered to 5 and 3 subgroups. These differences in genetic variation between land races of Korean ginseng implied the potential source for further breeding of Korean ginseng.

The Selection of Appropriate Sampler for the Assessment of Macrobenthos Community in Saemangeum, the West Coast of Korea (새만금 외해역에서 대형 저서동물 군집 조사를 위한 적정 채집기의 선택)

  • 유재원;김창수;박미라;이형곤;이재학;홍재상
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.8 no.3
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    • pp.285-294
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    • 2003
  • To select an appropriate sampler for the environmental monitoring survey in coastal waters of Saemangeum, Jeollabuk-do, a macrobenthic sampling was conducted in April 2002. Employed samplers were dredge (type Charcot), a semi-quantitative sampler and Smith-McIntyre (SM) and van Veen grab (VV) as quantitative ones. One haul was tried for dredge and 3 replicates (0.1 ㎡${\times}$3) for SM and W at each of 11 stations. Comparisons of sediment volume in sampler bucket and of precision of biological parameters (i.e., density, biomass, species number and diversity index, H') were made between SM and VV. Sediment volume was significantly different (SM > VV) at p-value of 0.0050 (paired t-test) and, in average, 3 replicate samples of SM and VV satisfied a precision level of 0.2 by applying 4th root transformation. Patterns of observed and expected species numbers and H' were compared. Dredge-VV samples showed higher affinity than any other pair. Several dominant species in the area were underestimated in dredge samples (e.g., polychaete Heteromastus filiformis. Aricidea assimilis etc.). Quantifying the agreement pattern of multi-species responses was accomplished by estimating correlations between similarity matrices. Correlation between dredge and VV was slightly higher, but near-per-fect matches were found in general. Different ranks and composition among principal species lists were presumably linked to the effect of penetration depth that differs among samplers. Lower level of some species' abundance in VV samples (ca. 50% compared with those of SM) was explained in this context. It seem appropriate to regard the effect as a probable cause of relatively higher correlations in dredge-VV, Overall bio-logica1 features indicated that a better choice could be SM in situations of requiring high data quality. The others work well, however, on observing and defining faunal characteristics and their capability cannot be questionted if we do not expect a first-order quality.