• 제목/요약/키워드: cluster analyses

검색결과 455건 처리시간 0.027초

주력산업에서 가치전략과 재무성과의 상관관계 (Correlation between Value Strategies and Financial Performance in Leading Industries)

  • 홍기철;박광호
    • 산업경영시스템학회지
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    • 제41권1호
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    • pp.70-83
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    • 2018
  • Korea's five leading industries-chemical, automobile, shipbuilding, metal and electronics-have been the growth engines of the Korean economy for the last 30 years. However, with their performance weakening in the past few years, Korea's annual growth rate has dropped to less than 2%. Just as the Japanese economy struggled through the lost decades, Korea's leading industries have been facing signals of arriving at a Strategic Inflection Point ("SIP") since the mid-2000s. The objective of this study is to present an appropriate value strategy for Korean firms in leading industries to gain sustainable competitive advantages. This paper examines the following issues : First, it diagnoses the signs and timing of SIP for the five leading industries. Second, this study examines 78 Korean and Japanese firms in order to understand the adaptation strategies of the highest and lowest performing firms from a value strategy point of view. Third, it empirically analyzes the correlation between the indicators of value strategy and the accounting performances of the Korean and Japanese firms. The data set used in the cluster analysis were collected from KISLINE database of NICE Information Service and annual reports. The findings in the case analyses of high and low performing companies show that high value-added specialty chemical materials and electronic component manufacturers that had a strong focus on value creation were defined as high performing companies. And in the cosmetic and automobile industries, companies with a strong emphasis on value appropriation gained high performance. Furthermore, the study conducted a cluster analysis based on two indicators R&D and advertisement expense. The analysis shows that a significant gap exists in the operating incomes among three groups classified under the value strategy. The study recommends that Korean firms are requested to increase R&D expenditure, conduct M&A and collaborate with companies that own source technologies to narrow the technology gap and improve their segment portfolio from commodity to value-added products.

Complexity Analysis of the Viking Labeled Release Experiments

  • Bianciardi, Giorgio;Miller, Joseph D.;Straat, Patricia Ann;Levin, Gilbert V.
    • International Journal of Aeronautical and Space Sciences
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    • 제13권1호
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    • pp.14-26
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    • 2012
  • The only extraterrestrial life detection experiments ever conducted were the three which were components of the 1976 Viking Mission to Mars. Of these, only the Labeled Release experiment obtained a clearly positive response. In this experiment $^{14}C$ radiolabeled nutrient was added to the Mars soil samples. Active soils exhibited rapid, substantial gas release. The gas was probably $CO_2$ and, possibly, other radiocarbon-containing gases. We have applied complexity analysis to the Viking LR data. Measures of mathematical complexity permit deep analysis of data structure along continua including signal vs. noise, entropy vs.negentropy, periodicity vs. aperiodicity, order vs. disorder etc. We have employed seven complexity variables, all derived from LR data, to show that Viking LR active responses can be distinguished from controls via cluster analysis and other multivariate techniques. Furthermore, Martian LR active response data cluster with known biological time series while the control data cluster with purely physical measures. We conclude that the complexity pattern seen in active experiments strongly suggests biology while the different pattern in the control responses is more likely to be non-biological. Control responses that exhibit relatively low initial order rapidly devolve into near-random noise, while the active experiments exhibit higher initial order which decays only slowly. This suggests a robust biological response. These analyses support the interpretation that the Viking LR experiment did detect extant microbial life on Mars.

Spatiotemporal Clusters and Trends of Pneumocystis Pneumonia in Korea

  • Kim, Hwa Sun;Nam, Ho-Woo;Ahn, Hye-Jin;Lee, Sang Haak;Kim, Yeong Hoon
    • Parasites, Hosts and Diseases
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    • 제60권5호
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    • pp.327-338
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    • 2022
  • This study determined the recent status and trend of Pneumocystis jirovecii pneumonia (PcP) in the non-human immunodeficiency virus (HIV) (non-HIV-PcP) and HIV (HIV-PcP) infected populations using data from the Health Insurance Review & Assessment Service (HIRA) and the Korea Disease Control and Prevention Agency (KDCA). SaTScan and Join-point were used for statistical analyses. Non-HIV-PcP cases showed an upward trend during the study period from 2010 to 2021, with the largest number in 2021 (551 cases). The upward trend was similar until 2020 after adjusting for the population. Seoul had the highest number of cases (1,597) in the non-HIV-PcP group, which was the same after adjusting for the population (162 cases/1,000,000). It was followed by Jeju-do (89 cases/1,000,000). The most likely cluster (MLC) for the non-HIV-PCP group was Seoul (Relative Risk (RR)=4.59, Log Likelihood Ratio (LLR)=825.531), followed by Jeju-do (RR=1.59, LLR=5.431). An upward trend was observed among the non-HIV-PcP group in the Jeju-do/Jeollanam-do/Jeollabuk-do/Gyeongsangnam-do/Busan/Daejeon/Daegu/Ulsan joint cluster (29.02%, LLR=11.638, P<0.001) located in the southern part of Korea. Both women and men in the non-HIV groups showed an overall upward trend of PcP during the study period. Men in the 60-69 age group had the highest annual percentage change (APC 41.8) during 2014-2019. In contrast, the HIV groups showed a falling trend of PcP recently. Men in the 60-69 age group had the most decrease (APC -17.6) during 2018-2021. This study provides an analytic basis for health measures and a nationwide epidemiological surveillance system for the management of PcP.

Relationship between Clonorchis sinensis Infection and Cholangiocarcinoma in Korea

  • Kim, Hwa Sun;Nam, Ho-Woo;Ahn, Hye-Jin;Kim, Dongjae;Kim, Yeong Hoon
    • Parasites, Hosts and Diseases
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    • 제60권4호
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    • pp.261-271
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    • 2022
  • This study provides an overview of the current status of clonorchiasis and cholangiocarcinoma (CCA), and their relationship in Korea during 2012-2020. Data were obtained from the Health Insurance Review & Assessment Service of Korea. Cluster, trend, and correlation analyses were performed. Gyeongsangnam-do and Seoul had the highest average number of cases (1,026 and 4,208) and adjusted rate (306 and 424) for clonorchiasis and CCA, respectively. The most likely clusters (MLC) for clonorchiasis and CCA were Busan/Gyeongsangnam-do/Ulsan/Daegu/Gyeongsangbuk-do (Relative Risk; RR=4.55, Likelihood Ratio; LLR=9,131.115) joint cluster and Seoul (RR=2.29, LLR=7,602.472), respectively. The MLC for clonorchiasis was in the southeastern part of Korea, while that for CCA was in the southern part. Clonorchiasis showed a decreasing trend in the southeastern districts, while increased in the southwestern districts. Cities in the central region had a decreasing trend, while the western districts had an increasing trend. In most adults (30-59), infection rate of clonorchiasis showed a significant decrease until 2018, while thereafter increased, although not significant. CCA showed a sharply decreasing tendency. The incidence of clonorchiasis and CCA were positively correlated. In general, the correlation was weak (r=0.39, P<0.001), but it was strongly positive around the 4 river basins (r=0.74, P<0.001). This study might provide an analytic basis for developing an effective system against clonorchiasis and CCA.

Characterization of facial asymmetry phenotypes in adult patients with skeletal Class III malocclusion using three-dimensional computed tomography and cluster analysis

  • Ha, Sang-Woon;Kim, Su-Jung;Choi, Jin-Young;Baek, Seung-Hak
    • 대한치과교정학회지
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    • 제52권2호
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    • pp.85-101
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    • 2022
  • Objective: To classify facial asymmetry (FA) phenotypes in adult patients with skeletal Class III (C-III) malocclusion. Methods: A total of 120 C-III patients who underwent orthognathic surgery (OGS) and whose three-dimensional computed tomography images were taken one month prior to OGS were evaluated. Thirty hard tissue landmarks were identified. After measurement of 22 variables, including cant (°, mm), shift (mm), and yaw (°) of the maxilla, maxillary dentition (Max-dent), mandibular dentition, mandible, and mandibular border (Man-border) and differences in the frontal ramus angle (FRA, °) and ramus height (RH, mm), K-means cluster analysis was conducted using three variables (cant in the Max-dent [mm] and shift [mm] and yaw [°] in the Manborder). Statistical analyses were conducted to characterize the differences in the FA variables among the clusters. Results: The FA phenotypes were classified into five types: 1) non-asymmetry type (35.8%); 2) maxillary-cant type (14.2%; severe cant of the Max-dent, mild shift of the Man-border); 3) mandibular-shift and yaw type (16.7%; moderate shift and yaw of the Man-border, mild RH-difference); 4) complex type (9.2%; severe cant of the Max-dent, moderate cant, severe shift, and severe yaw of the Man-border, moderate differences in FRA and RH); and 5) maxillary reverse-cant type (24.2%; reverse-cant of the Max-dent). Strategic decompensation by pre-surgical orthodontic treatment and considerations for OGS planning were proposed according to the FA phenotypes. Conclusions: This FA phenotype classification may be an effective tool for differential diagnosis and surgical planning for Class III patients with FA.

텍스트 마이닝을 통한 건설공사 공문 잠재적 리스크 유형 분석 (Analysis of Potential Construction Risk Types in Formal Documents Using Text Mining)

  • 엄세호;차기춘;박선규;박승희;박종호
    • 대한토목학회논문집
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    • 제43권1호
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    • pp.91-98
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    • 2023
  • 건설프로젝트에서 발생되는 리스크는 공기지연 및 비용증가에 큰 영향을 끼치기 때문에 다양한 리스크를 파악하기 위한 노력이 이루어지고 있다. 그러나 시공단계의 리스크 분석은 공종 및 수행단계에 국한되거나, 경험 의존적 의사결정이 주로 수행되고 있다. 데이터 기반의 분석도 일부 사례에 적용되고 있을 뿐이다. 따라서 본 연구에서는 시공사 또는 발주처에 중요한 요인들이 포함되어 있을 것으로 판단되는 수발신공문을 대상으로 군집분석과 Word2Vec 알고리즘을 적용하였다. 군집분석을 통해 6개 유형으로 1차 분류를 수행하였으며, Word2Vec을 통해 157개의 공문 발생 유형을 도출하였다. 도출된 연관어의 속성별 분석을 위하여 새로운 5개의 범주를 적용하였으며, 이를 통해 공문 발생 유형이 잠재적인 건설 리스크 요인으로 발전 가능한지 검토하였다. 텍스트 마이닝을 통한 3단계의 공문 발생 유형 분석 결과는 건설현장의 공정관리를 위한 기초 자료로써 도움 될 것으로 판단된다.

빈도별 확률강우량을 초과하는 시간강우사상의 특성 분석 (Characteristics Analyses of Timely Rainfall Events Above Probability Precipitation on Each Frequency)

  • 오태석;김은철;문영일;안재현
    • 대한토목학회논문집
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    • 제29권6B호
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    • pp.513-526
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    • 2009
  • 홍수피해를 줄이기 위해 적정한 설계빈도에 맞는 치수대책을 수립한다. 일반적으로 설계빈도는 지역의 현황, 중요도뿐만 아니라 확률강우량 등을 반영한다. 따라서 본 연구에서는 최근 10년간 주요 호우사상에 의해 홍수피해가 발생한 지역을 대상으로 지속시간별로 최대강우량의 빈도를 산정하였다. 그리고 빈도별 확률강우량을 초과하는 강우사상의 시간적 특성을 분석하기 위해 초과강우량과 초과횟수 및 단위초과강우량을 산정하여 변동성과 경향성 분석을 수행하였다. 또한 강우관측소의 위치와 시간강우량 특성을 이용해 군집분석을 실시하고 강우관측소를 군집화 하였다. 군집된 지역을 대상으로 평균초과강우량과 평균초과횟수 및 평균단위초과강우량을 산정하였고, 군집지역별 초과강우량과 초과횟수에 대해 변동성 및 경향성을 분석을 실시하여 시간적 변화를 비교하였다.

울산시민의 건강실천을 위한 식생활 행태 (Dietary Behaviors of Adults for Health in Ulsan City)

  • 신애숙;김광기
    • 한국식생활문화학회지
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    • 제15권1호
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    • pp.17-28
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    • 2000
  • This paper is an effort to describe dietary behaviors to keep them healthy among adults. A probability sample was drawn from residents aged between 15 and 60 living in Ulsan City area through a multi-staged cluster sampling method. The data collected by face-to-face interview includes 1,232 respondents. Both univariate and bivariate analyses were employed to describe the dietary behaviors. The dietary behaviors in this study includes preference of taking fat-part of meat, fried food, salty food, hot-taste food, drinking coffee and milk, and taking supplementary medicine. About half of the respondents reported to take fat removed when eating meat, and more than 68% of them preferred not to take any kinds of fried food. With respect to preference of salty and hot-taste food, 39.6% of the respondents take medium-salty and 39.4% do hot-taste food. A third of the respondents drink two-four cups of coffee a day. Those who reported not to drink milk at all were prevalent(37.4% of the respondents) than expected. However, less than 20% of the respondents reported to have any kinds of supplementary health food in a year. These dietary behaviors were examined by sociodemographic characteristics for bivariate analyses.

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Analysis of Genetic Variation in Botrytis cinerea Isolates Using Random Amplified Polymorphic DNA Markers

  • Choi, In-Sil;Kim, Dae-Hyuk;Lee, Chang-Won;Kim, Jae-Won;Chung, Young-Ryun
    • Journal of Microbiology and Biotechnology
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    • 제8권5호
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    • pp.490-496
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    • 1998
  • Random amplified polymorphic DNA (RAPD) markers were used to survey genetic variability among 34 Botrytis cinerea isolates from nine different host plants in Korea. For RAPD analysis, 115 arbitrary decamer primers were initially screened for polymorphic major DNA bands with 11 representative B. cinerea isolates. Eleven primers that initially detected polymorphisms were tested a second time with additional 23 isolates of B. cinerea as well as one isolate of Botrytis squamosa as an outgroup. The RAPD analyses revealed that all isolates except one showed different molecular phenotypes. Dendrograms obtained from dissimilarity matrices using the unweighted paired group method of arithmetic means (UPGMA) showed the 36.4% to 90.0% similarity among all B. cinerea isolates. The B. squamosa isolate showed the least similarity to all B. cinerea isolates. The cluster analyses indicated no correlation among all the characteristics examined including molecular phenotypes, host and geographic origins, year of isolation, or pathogenicity. The RAPD data suggest that a high level of genetic variation exists among Korean populations of B. cinerea and it seems to be caused by heterokaryosis among preexisting molecular phenotypes.

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Discrimination of Bacillus anthracis Spores by Direct in-situ Analysis of Matrix-Assisted Laser Desorption/Ionization Time-Of-Flight Mass Spectrometry

  • Jeong, Young-Su;Lee, Jonghee;Kim, Seong-Joo
    • Bulletin of the Korean Chemical Society
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    • 제34권9호
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    • pp.2635-2639
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    • 2013
  • The rapid and accurate identification of biological agents is a critical step in the case of bio-terror and biological warfare attacks. Recently, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry has been widely used for the identification of microorganisms. In this study, we describe a method for the rapid and accurate discrimination of Bacillus anthracis spores using MALDI-TOF MS. Our direct in-situ analysis of MALDI-TOF MS does not involve subsequent high-resolution mass analyses and sample preparation steps. This method allowed the detection of species-specific biomarkers from each Bacillus spores. Especially, B. anthracis spores had specific biomarker peaks at 2503, 3089, 3376, 6684, 6698, 6753, and 6840 m/z. Cluster and PCA analyses of the mass spectra of Bacillus spores revealed distinctively separated clusters and within-groups similarity. Therefore, we believe that this method is effective in the real-time identification of biological warfare agents such as B. anthracis as well as other microorganisms in the field.