• Title/Summary/Keyword: k-means clustering analysis

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Application of Spatial Autocorrelation for the Spatial Distribution Pattern Analysis of Marine Environment - Case of Gwangyang Bay - (해양환경 공간분포 패턴 분석을 위한 공간자기상관 적용 연구 - 광양만을 사례 지역으로 -)

  • Choi, Hyun-Woo;Kim, Kye-Hyun;Lee, Chul-Yong
    • Journal of the Korean Association of Geographic Information Studies
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    • v.10 no.4
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    • pp.60-74
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    • 2007
  • For quantitative analysis of spatio-temporal distribution pattern on marine environment, spatial autocorrelation statistics on the both global and local aspects was applied to the observed data obtained from Gwangyang Bay in South Sea of Korea. Global indexes such as Moran's I and General G were used for understanding environmental distribution pattern in the whole study area. LISAs (local indicators of spatial association) such as Moran's I ($I_i$) and $G_i{^*}$ were considered to find similarity between a target feature and its neighborhood features and to detect hot spot and/or cold spot. Additionally, the significance test on clustered patterns by Z-scores was carried out. Statistical results showed variations of spatial patterns quantitatively in the whole year. Then all of general water quality, nutrients, chlorophyll-a and phytoplankton had strong clustered pattern in summer. When global indexes showed strong clustered pattern, the front region with a negative $I_i$ which means a strong spatial variation was observed. Also, when global indexes showed random pattern, hot spot and/or cold spot were/was found in the small local region with a local index $G_i{^*}$. Therefore, global indexes were useful for observing the strength and time series variations of clustered patterns in the whole study area, and local indexes were useful for tracing the location of hot spot and/or cold spot. Quantification of both spatial distribution pattern and clustering characteristics may play an important role to understand marine environment in depth and to find the reasons for spatial pattern.

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Preference Differences in Interior Images of Restaurants according to Lifestyles (라이프스타일 유형에 따른 레스토랑 실내이미지 선호도 차이에 관한 연구)

  • Kim, Tae-Hee;Park, Young-Seok
    • Journal of the Korean Home Economics Association
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    • v.43 no.10 s.212
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    • pp.69-79
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    • 2005
  • The purpose of this study was to determine restaurant patrons' preference differences in interior design style of restaurants according to their lifestyles. Written questionnaires were handed out to 500 adults in Seoul and surroundings and the results were sampled by convenience sampling. The questionnaire was composed of respondents' general characteristics, lifestyles, and preference for 10 types of interior design style. A total of 415 questionnaires were usable for data analysis, resulting in a response rate of $83\%$. To analyze the collected data, frequency, factor, reliability, quick clustering K- means and One-Way ANOVA analysis were conducted using SPSS 10.0. The results showed that there were preference differences in 10 types of interior design style of restaurants according to lifestyle types which were categorized into 4 groups. The conservative and self-convinced group showed the lowest preference scores in the 10 types of interior design style which are Romantic, Ethnic, Classic, High-Tech, Elegant, Country, Modem, Minimal, Natural, and Casual style. The quality life pursuing group and extroverted individuality groups showed the high preference scores in most of the styles, especially in the Classic and Elegant styles. The realistic self-centered group showed the highest preference scores in Casual style among the 4 groups. These study findings indicate that restaurants should take into account their patrons' lifestyles as a mean of market segmentation, and respond to their taste and preference when they have established suitable servicescape.

Impact of Difference in Korean Wave Awareness among Chinese Women on Quality Perception and Purchasing Behavior of Korean Cosmetic Products (중국여성의 한류 인지도 차이가 한국 화장품에 대한 품질인식과 구매행동에 미치는 영향)

  • Lee, Jeong-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.10
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    • pp.5097-5104
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    • 2013
  • To derive implication for marketing strategy for Korean cosmetic products in China, an analysis was conducted on the difference in quality perception and purchase behavior between two groups of Chinese women classified by their awareness of Korean Wave. Analytical methods including k-means clustering method, independent samples t-test, factor analysis were applied on the survey results of Chinese women residing in Guangzhou city. The positive impact of Korean Wave on quality perception and brand image is much stronger for higher awareness group, compared against for lower awareness group, that leads to higher product satisfaction and willingness to recommend purchases. Thus, marketing strategies need to be adjusted based on the difference in customers awareness of Korean Wave. However, the low price is the primary inducement for purchases for both groups, increased efforts to enhance brand image and product quality as premium products is strongly required, together with the utilization of Koran Wave.

Design of pRBFNNs Pattern Classifier-based Face Recognition System Using 2-Directional 2-Dimensional PCA Algorithm ((2D)2PCA 알고리즘을 이용한 pRBFNNs 패턴분류기 기반 얼굴인식 시스템 설계)

  • Oh, Sung-Kwun;Jin, Yong-Tak
    • Journal of the Institute of Electronics and Information Engineers
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    • v.51 no.1
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    • pp.195-201
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    • 2014
  • In this study, face recognition system was designed based on polynomial Radial Basis Function Neural Networks(pRBFNNs) pattern classifier using 2-directional 2-dimensional principal component analysis algorithm. Existing one dimensional PCA leads to the reduction of dimension of image expressed by the multiplication of rows and columns. However $(2D)^2PCA$(2-Directional 2-Dimensional Principal Components Analysis) is conducted to reduce dimension to each row and column of image. and then the proposed intelligent pattern classifier evaluates performance using reduced images. The proposed pRBFNNs consist of three functional modules such as the condition part, the conclusion part, and the inference part. In the condition part of fuzzy rules, input space is partitioned with the aid of fuzzy c-means clustering. In the conclusion part of rules. the connection weight of RBFNNs is represented as the linear type of polynomial. The essential design parameters (including the number of inputs and fuzzification coefficient) of the networks are optimized by means of Differential Evolution. Using Yale and AT&T dataset widely used in face recognition, the recognition rate is obtained and evaluated. Additionally IC&CI Lab dataset is experimented with for performance evaluation.

Assessment through Statistical Methods of Water Quality Parameters(WQPs) in the Han River in Korea

  • Kim, Jae Hyoun
    • Journal of Environmental Health Sciences
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    • v.41 no.2
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    • pp.90-101
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    • 2015
  • Objective: This study was conducted to develop a chemical oxygen demand (COD) regression model using water quality monitoring data (January, 2014) obtained from the Han River auto-monitoring stations. Methods: Surface water quality data at 198 sampling stations along the six major areas were assembled and analyzed to determine the spatial distribution and clustering of monitoring stations based on 18 WQPs and regression modeling using selected parameters. Statistical techniques, including combined genetic algorithm-multiple linear regression (GA-MLR), cluster analysis (CA) and principal component analysis (PCA) were used to build a COD model using water quality data. Results: A best GA-MLR model facilitated computing the WQPs for a 5-descriptor COD model with satisfactory statistical results ($r^2=92.64$,$Q{^2}_{LOO}=91.45$,$Q{^2}_{Ext}=88.17$). This approach includes variable selection of the WQPs in order to find the most important factors affecting water quality. Additionally, ordination techniques like PCA and CA were used to classify monitoring stations. The biplot based on the first two principal components (PCs) of the PCA model identified three distinct groups of stations, but also differs with respect to the correlation with WQPs, which enables better interpretation of the water quality characteristics at particular stations as of January 2014. Conclusion: This data analysis procedure appears to provide an efficient means of modelling water quality by interpreting and defining its most essential variables, such as TOC and BOD. The water parameters selected in a COD model as most important in contributing to environmental health and water pollution can be utilized for the application of water quality management strategies. At present, the river is under threat of anthropogenic disturbances during festival periods, especially at upstream areas.

Delineation of Rice Productivity Projected via Integration of a Crop Model with Geostationary Satellite Imagery in North Korea

  • Ng, Chi Tim;Ko, Jonghan;Yeom, Jong-min;Jeong, Seungtaek;Jeong, Gwanyong;Choi, Myungin
    • Korean Journal of Remote Sensing
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    • v.35 no.1
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    • pp.57-81
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    • 2019
  • Satellite images can be integrated into a crop model to strengthen the advantages of each technique for crop monitoring and to compensate for weaknesses of each other, which can be systematically applied for monitoring inaccessible croplands. The objective of this study was to outline the productivity of paddy rice based on simulation of the yield of all paddy fields in North Korea, using a grid crop model combined with optical satellite imagery. The grid GRAMI-rice model was used to simulate paddy rice yields for inaccessible North Korea based on the bidirectional reflectance distribution function-adjusted vegetation indices (VIs) and the solar insolation. VIs and solar insolation for the model simulation were obtained from the Geostationary Ocean Color Imager (GOCI) and the Meteorological Imager (MI) sensors of the Communication Ocean and Meteorological Satellite (COMS). Reanalysis data of air temperature were achieved from the Korea Local Analysis and Prediction System (KLAPS). Study results showed that the yields of paddy rice were reproduced with a statistically significant range of accuracy. The regional characteristics of crops for all of the sites in North Korea were successfully defined into four clusters through a spatial analysis using the K-means clustering approach. The current study has demonstrated the potential effectiveness of characterization of crop productivity based on incorporation of a crop model with satellite images, which is a proven consistent technique for monitoring of crop productivity in inaccessible regions.

Motherhood Ideology and Parenting Stress according to Parenting Behavior Patterns of Married Immigrant Women with Young Children (유아기 자녀를 둔 결혼이주여성의 양육행위 유형별 모성이데올로기 및 양육스트레스)

  • Moon, So-Hyun;Kim, Miok;Na, Hyeun
    • Journal of Korean Academy of Nursing
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    • v.49 no.4
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    • pp.449-460
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    • 2019
  • Purpose: This study aims to provide base data for designing education and counseling programs for child-raising by identifying the types, characteristics and predictors of parenting behaviors of married immigrant women. Methods: We used a self-report questionnaire to survey 126 immigrant mothers of young children, who agreed to participate, and who could speak Korean, Vietnamese, Chinese, Filipino, or English, at two children's hospitals and two multicultural support centers. Statistical analysis was conducted using descriptive analysis, K-means clustering, ${\chi}^2$ test, Fisher's exact test, one-way ANOVA, $Sch{\acute{e}}ffe^{\prime}s$ test, and multinominal logistic regression. Results: We identified three clusters of parenting behaviors: 'affectionate acceptance group' (38.9%), 'active engaging group' (26.2%), and 'passive parenting group' (34.9%). Passive parenting and affectionate acceptance groups were distinguished by the conversation time between couples (p=.028, OR=5.52), ideology of motherhood (p=.032, OR=4.33), and parenting stress between parent and child (p=.049, OR=0.22). Passive parenting was distinguished from active engaging group by support from spouses for participating in multicultural support centers or relevant programs (p=.011, OR=2.37), and ideology of motherhood (p=.001, OR=16.65). Ideology of motherhood was also the distinguishing factor between affectionate acceptance and active engaging groups (p=.041, OR=3.85). Conclusion: Since immigrant women's parenting type depends on their ideology of motherhood, parenting stress, and spousal relationships in terms of communication and support to help their child-raising and socio-cultural adaptation, it is necessary to provide them with systematic education and support, as well as interventions across personal, family, and community levels.

Analyzing fashion item purchase patterns and channel transition patterns using association rules and brand loyalty in big data (빅데이터의 연관규칙과 브랜드 충성도를 활용한 패션품목 구매패턴과 구매채널 전환패턴 분석)

  • Ki Yong Kwon
    • The Research Journal of the Costume Culture
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    • v.32 no.2
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    • pp.199-214
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    • 2024
  • Until now, research on consumers' purchasing behavior has primarily focused on psychological aspects or depended on consumer surveys. However, there may be a gap between consumers' self-reported perceptions and their observable actions. In response, this study aimed to investigate consumer purchasing behavior utilizing a big data approach. To this end, this study investigated the purchasing patterns of fashion items, both online and in retail stores, from a data-driven perspective. We also investigated whether individual consumers switched between online websites and retail establishments for making purchases. Data on 516,474 purchases were obtained from fashion companies. We used association rule analysis and K-means clustering to identify purchase patterns that were influenced by customer loyalty. Furthermore, sequential pattern analysis was applied to investigate the usage patterns of online and offline channels by consumers. The results showed that high-loyalty consumers mainly purchased infrequently bought items in the brand line, as well as high-priced items, and that these purchase patterns were similar both online and in stores. In contrast, the low-loyalty group showed different purchasing behaviors for online versus in-store purchases. In physical environments, the low-loyalty consumers tended to purchase less popular or more expensive items from the brand line, whereas in online environments, their purchases centered around items with relatively high sales volumes. Finally, we found that both high and low loyalty groups exclusively used a single preferred channel, either online or in-store. The findings help companies better understand consumer purchase patterns and build future marketing strategies around items with high brand centrality.

Analysis method of patent document to Forecast Patent Registration (특허 등록 예측을 위한 특허 문서 분석 방법)

  • Koo, Jung-Min;Park, Sang-Sung;Shin, Young-Geun;Jung, Won-Kyo;Jang, Dong-Sik
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.4
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    • pp.1458-1467
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    • 2010
  • Recently, imitation and infringement rights of an intellectual property are being recognized as impediments to nation's industrial growth. To prevent the huge loss which comes from theses impediments, many researchers are studying protection and efficient management of an intellectual property in various ways. Especially, the prediction of patent registration is very important part to protect and assert intellectual property rights. In this study, we propose the patent document analysis method by using text mining to predict whether the patent is registered or rejected. In the first instance, the proposed method builds the database by using the word frequencies of the rejected patent documents. And comparing the builded database with another patent documents draws the similarity value between each patent document and the database. In this study, we used k-means which is partitioning clustering algorithm to select criteria value of patent rejection. In result, we found conclusion that some patent which similar to rejected patent have strong possibility of rejection. We used U.S.A patent documents about bluetooth technology, solar battery technology and display technology for experiment data.

Class Imbalance Resolution Method and Classification Algorithm Suggesting Based on Dataset Type Segmentation (데이터셋 유형 분류를 통한 클래스 불균형 해소 방법 및 분류 알고리즘 추천)

  • Kim, Jeonghun;Kwahk, Kee-Young
    • Journal of Intelligence and Information Systems
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    • v.28 no.3
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    • pp.23-43
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    • 2022
  • In order to apply AI (Artificial Intelligence) in various industries, interest in algorithm selection is increasing. Algorithm selection is largely determined by the experience of a data scientist. However, in the case of an inexperienced data scientist, an algorithm is selected through meta-learning based on dataset characteristics. However, since the selection process is a black box, it was not possible to know on what basis the existing algorithm recommendation was derived. Accordingly, this study uses k-means cluster analysis to classify types according to data set characteristics, and to explore suitable classification algorithms and methods for resolving class imbalance. As a result of this study, four types were derived, and an appropriate class imbalance resolution method and classification algorithm were recommended according to the data set type.