• Title/Summary/Keyword: cluster sets

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Implementation of an Artificial Odour Recognition System with Unsupervised Clustering Methods (Unsupervised clustering 방법을 갖는 인공 냄새인식 시스템의 구현)

  • Choi, Chan-Seok;Kim, Jeong-Do;Byun, Hyung-Gi
    • Journal of Sensor Science and Technology
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    • v.10 no.6
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    • pp.310-316
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    • 2001
  • We have been designed and constructed an artificial odour recognition system(electronic nose system) using metal oxide type sensor array for recognizing and analyzing various odours. We proposed an unsupervised clustering method based on Euclidean distances in order for human observer to examine easily multi-dimensional data, which has been measured from an array of sensors. This is a combination of Principal Components Analysis(PCA) used as a starting point for Sammom Mapping Method(SMM). No prior assumptions are made of the classes in which odour belong, and the error due to dimensional reduction at the PCA can be minimized without the disadvantages of rotation of clusters when the order of data sets in a data base was changed in the SMM. An artificial odour recognition system with the proposed unsupervised clustering method was applied to assessment of odour differences of Volatile Organic Compounds(VOCs) and Korean whiskies respectively, and demonstrated the best performances throughout the experimental trails.

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A GIS-Based Method for Delineating Spatial Clusters: A Modified AMOEBA Technique (공간 클러스터의 범역 설정을 위한 GIS-기반 방법론 연구 -수정 AMOEBA 기법-)

  • Lee, Sang-Il;Cho, Dae-Heon;Sohn, Hak-Gi;Chae, Mi-Ok
    • Journal of the Korean Geographical Society
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    • v.45 no.4
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    • pp.502-520
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    • 2010
  • The main objective of the paper is to develop a GIS-based method for delineating spatial clusters. Major tasks are: (i) to devise a sustainable algorithm with reference to various methods developed in the fields of geographic boundary analysis and cluster detection; (ii) to develop a GIS-based program to implement the algorithm. The main results are as follows. First, it is recognized that the AMOEBA technique utilizing LISA is the best candidate. Second, a modified version of the AMOEBA technique is proposed and implemented in a GIS environment. Third, the validity and usefulness of the modified AMOEBA algorithm is assured by its applications to test and real data sets.

Geostatistical Interpretation of Water Quality and Hydrogeochemistry of shallow Groundwater in the Uljin Area, Korea (지구통계 기법을 활용한 울진 지역 천부 지하수의 수질 및 수리지구화학 특성 해석)

  • 김남진;윤성택;김형수;정경문;김규범
    • Economic and Environmental Geology
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    • v.34 no.2
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    • pp.175-192
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    • 2001
  • We have collected hydrogeochemical data of shallow groundwaters in the Uljin area located at eastern coastal area of Korea. Geostatistical analysis (ANOVA test, cluster analysis, and factor analysis) of the collected data sets was pert'onned, in order to evaluate both the spatial and/or temporal variation of water quality data and the groundwater contamination, as weJl as the principal reactions occurring in the aquifer. Results of the ANOVA test show that regional water chemistry are not significantly changed spatially in eight watersheds. However, some ions such as $Ca^{2+}$, $HCO_{3}^{-}$ and $SO_{4}^{2-}$ show a meaningful watershed variation. Water chemistry variation according to sampling time (season) is not shown, except for $SO_{4}^{2-}$. The cluster analysis shows that significant water chemistry variation is eXplained by the distance from the coast. Factor analysis indicates that the water chemistry is changed according to various factors as follows: in the order of decreasing importance, water-rock interaction (mainly, carbonate dissolution), sea-salt spraying, and then contamination by fertilizers and agrochemicals.

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Some Calculated (p,α) Cross-Sections Using the Alpha Particle Knock-On and Triton Pick-Up Reaction Mechanisms: An Optimisation of the Single-Step Feshbache-Kermane-Koonin (FKK) Theory

  • Olise, Felix S.;Ajala, Afis;Olaniyi, Hezekiah B.
    • Nuclear Engineering and Technology
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    • v.48 no.2
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    • pp.482-494
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    • 2016
  • The Feshbache-Kermane-Koonin (FKK) multi-step direct (MSD) theory of pre-equilibrium reactions has been used to compute the single-step cross-sections for some (p,${\alpha}$) reactions using the knock-on and pick-up reaction mechanisms at two incident proton energies. For the knock-on mechanism, the reaction was assumed to have taken place by the direct ejection of a preformed alpha cluster in a shell-model state of the target. But the reaction was assumed to have taken place by the pick-up of a preformed triton cluster (also bound in a shell-model state of the target core) by the incident proton for the pick-up mechanism. The Yukawa forms of potential were used for the proton-alpha (for the knock-on process) and proton-triton (for the pick-up process) interaction and several parameter sets for the proton and alpha-particle optical potentials. The calculated cross-sections for both mechanisms gave satisfactory fits to the experimental data. Furthermore, it has been shown that some combinations of the calculated distorted wave Born approximation cross-sections for the two reaction mechanisms in the FKK MSD theory are able to give better fits to the experimental data, especially in terms of range of agreement. In addition, the theory has been observed to be valid over a wider range of energy.

A method for learning users' preference on fuzzy values using neural networks and k-means clustering (신경망과 k-means 클러스터링을 이용한 사용자의 퍼지값 선호도 학습 방법)

  • Yoon, Tae-Bok;Na, Hyun-Jong;Park, Doo-Kyung;Lee, Jee-Hyong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.16 no.6
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    • pp.716-720
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    • 2006
  • Fuzzy sets are good for abstracting and unifying information using natural language like terms. However, fuzzy sets embody vagueness and users may have different attitude to the vagueness, each user may choose difference one as the best among several fuzzy values. In this paper, we develop a method teaming a user's, preference on fuzzy values and select one which fits to his preference. Users' preferences are modeled with artificial neural networks. We gather learning data from users by asking to choose the best from two fuzzy values in several representative cases of comparing two fuzzy sets. In order to establish tile representative comparing cases, we enumerate more than 600 cases and cluster them into several groups. Neural networks ate trained with the users' answer and the given two fuzzy values in each case. Experiments show that the proposed method produces outputs closet to users' preference than other methods.

Evaluation of Genetic Diversity among Persimmon Cultivars (Diospyros kaki Thunb.) Using Microsatellite Markers (초위성 마커를 이용한 감(Diospyros kaki Thunb.)의 유연관계 분석)

  • Hwang, Ji-Hyeon;Park, Yu-Ok;Kim, Sung-Churl;Lee, Yong-Jae;Kang, Jum-Soon;Choi, Young-Whan;Son, Beung-Gu;Park, Young-Hoon
    • Journal of Life Science
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    • v.20 no.4
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    • pp.632-638
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    • 2010
  • The genetic diversity among 48 persimmon (Diospyros kaki Thunb.) accessions, indigenous in Korea and introduced from Japan and China, was evaluated by using simple sequence repeat (SSR) markers. From 20 SSR primer sets, a total of 114 polymorphic markers were detected among 12 pollination-constant non-astringent (PCNA), 13 pollination-variant non-astringent (PVNA), 15 pollination-variant astringent (PVA), and 8 pollination-constant astringent (PCA) cultivars. Analysis of pair-wise genetic similarity coefficient (Nei-Li) and unweighted pair-group method with arithmetic averaging (UPGMA) clustering revealed two main clusters and four subclusters for cluster I. The subclustering pattern was in accordance with the classification of persimmon cultivars based on the nature of astringency loss. Phenetic relationships among the subclusters showed a closer relatedness of the PCNA group with the PVNA group, and the PVA with the PCA group. Genetic similarity co-efficiency was 0.499 on average and the highest (0.954) similarity was observed between 'Cheongdo-Bansi' and 'Haman-Bansi'. The similarity was lowest (0.192) between 'Damopan'and 'Atago'. Identification of each cultivar with the execption of 'Cheongdo-Bansi' and 'Gyeongsan-Bansi' was possible based on the SSR fingerprints, suggesting that these SSR markers are a useful tool for protecting intellectual property on newly developed cultivars.

Survey of genetic structure of geese using novel microsatellite markers

  • Lai, Fang-Yu;Tu, Po-An;Ding, Shih-Torng;Lin, Min-Jung;Chang, Shen-Chang;Lin, En-Chung;Lo, Ling-Ling;Wang, Pei-Hwa
    • Asian-Australasian Journal of Animal Sciences
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    • v.31 no.2
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    • pp.167-179
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    • 2018
  • Objective: The aim of this study was to create a set of microsatellite markers with high polymorphism for the genetic monitoring and genetic structure analysis of local goose populations. Methods: Novel microsatellite markers were isolated from the genomic DNA of white Roman geese using short tandem repeated probes. The DNA segments, including short tandem repeats, were tested for their variability among four populations of geese from the Changhua Animal Propagation Station (CAPS). The selected microsatellite markers could then be used to monitor genetic variability and study the genetic structures of geese from local geese farms. Results: 14 novel microsatellite loci were isolated. In addition to seven known loci, two multiplex sets were constructed for the detection of genetic variations in geese populations. The average of allele number, the effective number of alleles, the observed heterozygosity, the expected heterozygosity, and the polymorphism information content were 11.09, 5.145, 0.499, 0.745, and 0.705, respectively. The results of analysis of molecular variance and principal component analysis indicated a contracting white Roman cluster and a spreading Chinese cluster. In white Roman populations, the CAPS populations were depleted to roughly two clusters when K was set equal to 6 in the Bayesian cluster analysis. The founders of private farm populations had a similar genetic structure. Among the Chinese geese populations, the CAPS populations and private populations represented different clads of the phylogenetic tree and individuals from the private populations had uneven genetic characteristics according to various analyses. Conclusion: Based on this study's analyses, we suggest that the CAPS should institute a proper breeding strategy for white Roman geese to avoid further clustering. In addition, for preservation and stable quality, the Chinese geese in the CAPS and the aforementioned proper breeding scheme should be introduced to geese breeders.

A Technique for Provisioning Virtual Clusters in Real-time and Improving I/O Performance on Computational-Science Simulation Environments (계산과학 시뮬레이션을 위한 실시간 가상 클러스터 생성 및 I/O 성능 향상 기법)

  • Choi, Chanho;Lee, Jongsuk Ruth;Kim, Hangi;Jin, DuSeok;Yu, Jung-lok
    • KIISE Transactions on Computing Practices
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    • v.21 no.1
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    • pp.13-18
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    • 2015
  • Computational science simulations have been used to enable discovery in a broad spectrum of application areas, these simulations show irregular demanding characteristics of computing resources from time to time. The adoption of virtualized high performance cloud, rather than CPU-centric computing platform (such as supercomputers), is gaining interest of interests mainly due to its ease-of-use, multi-tenancy and flexibility. Basically, provisioning a virtual cluster, which consists of a lot of virtual machines, in a real-time has a critical impact on the successful deployment of the virtualized HPC clouds for computational science simulations. However, the cost of concurrently creating many virtual machines in constructing a virtual cluster can be as much as two orders of magnitude worse than expected. One of the main factors in this bottleneck is the time spent to create the virtual images for the virtual machines. In this paper, we propose a novel technique to minimize the creation time of virtual machine images and improve I/O performance of the provisioned virtual clusters. We also confirm that our proposed technique outperforms the conventional ones using various sets of experiments.

A Study on Classification and Localization of Structural Damage through Wavelet Analysis

  • Koh, Bong-Hwan;Jung, Uk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.754-759
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    • 2007
  • This study exploits the data discriminating capability of silhouette statistics, which combines wavelet-based vertical energy threshold technique for the purpose of extracting damage-sensitive features and clustering signals of the same class. This threshold technique allows to first obtain a suitable subset of the extracted or modified features of our data, i.e., good predictor sets should contain features that are strongly correlated to the characteristics of the data without considering the classification method used, although each of these features should be as uncorrelated with each other as possible. The silhouette statistics have been used to assess the quality of clustering by measuring how well an object is assigned to its corresponding cluster. We use this concept for the discriminant power function used in this paper. The simulation results of damage detection in a truss structure show that the approach proposed in this study can be successfully applied for locating both open- and breathing-type damage even in the presence of a considerable amount of process and measurement noise.

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A Method for Clustering Noun Phrases into Coreferents for the Same Person in Novels Translated into Korean (한국어 번역 소설에서 인물명 명사구의 동일인물 공통참조 클러스터링 방법)

  • Park, Taekeun;Kim, Seung-Hoon
    • Journal of Korea Multimedia Society
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    • v.20 no.3
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    • pp.533-542
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    • 2017
  • Novels include various character names, depending on the genre and the spatio-temporal background of the novels and the nationality of characters. Besides, characters and their names in a novel are created by the author's pen and imagination. As a result, any proper noun dictionary cannot include all kinds of character names. In addition, the novels translated into Korean have character names consisting of two or more nouns (such as "Harry Potter"). In this paper, we propose a method to extract noun phrases for character names and to cluster the noun phrases into coreferents for the same character name. In the extraction of noun phrases, we utilize KKMA morpheme analyzer and CPFoAN character identification tool. In clustering the noun phrases into coreferents, we construct a directed graph with the character names extracted by CPFoAN and the extracted noun phrases, and then we create name sets for characters by traversing connected subgraphs in the directed graph. With four novels translated into Korean, we conduct a survey to evaluate the proposed method. The results show that the proposed method will be useful for speaker identification as well as for constructing the social network of characters.