• 제목/요약/키워드: two-stage cluster analysis

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Spatial Focalization of Zen-Meditation Brain Based on EEG

  • Liu, Chuan-Yi;Lo, Pei-Chen
    • 대한의용생체공학회:의공학회지
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    • 제29권1호
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    • pp.17-24
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    • 2008
  • The aim of this paper is to report our preliminary results of investigating the spatial focalization of Zen-meditation EEG (electroencephalograph) in alpha band (8-13 Hz). For comparison, the study involved two groups of subjects, practitioners (experimental group) and non-practitioners (control group). To extract EEG alpha rhythm, wavelet analysis was applied to multi-channel EEG signals. Normalized alpha-power vectors were then constructed from spatial distribution of alpha powers, that were classified by Fuzzy C-means based algorithm to explore various brain spatial characteristics during meditation (or, at rest). Optimal number of clusters was determined by correlation coefficients of the membership-value vectors of each cluster center. Our results show that, in the experimental group, the incidence of frontal alpha activity varied in accordance with the meditation stage. The results demonstrated three different spatiotemporal modules consisting with three distinctive meditation stages normally recognized by meditation practitioners. The frontal alpha activity in two groups decreased in different ways. Particularly, monotonic decline was observed in the control group, and the experimental group showed increasing results. The phenomenon might imply various mechanisms employed by meditation and relaxation in modulating parietal alpha.

Breast and Cervical Cancer Screening and Associated Factors among Older Adult Women in South Africa

  • Peltzer, Karl;Phaswana-Mafuya, Nancy
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권6호
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    • pp.2473-2476
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    • 2014
  • Background: Little is known about the cancer screening prevalence and correlates in older adults from different racial backgrounds. In the context of heightened efforts for prevention and early diagnosis, we collected information on screening for two major types of cancers: cervical and breast cancer in order to establish their prevalence estimates and correlates among older South African women who participated in the Study of Global Ageing and Adults Health (SAGE) in 2008. Materials and Methods: We conducted a national population-based cross-sectional study with a multi-stage stratified cluster sample of 3,840 individuals aged 50 years or older in South Africa in 2008. In this analysis, we only considered the female subsample of (n=2202). The measures used included socio-demographic characteristics, health variables, anthropometric and blood pressure measurements. Multivariable regression analysis was performed to assess the association of socio-demographic factors, health variables and cancer screening. Results: Overall, regarding cervical cancer screening, 24.3% ever had a Papanicolaou (PAP) smear test, and regarding breast cancer screening, 15.5% ever had a mammography. In multivariate logistic regression analysis, younger age, higher education, being from the White or Coloured population group, urban residence, greater wealth, and suffering from two or more chronic conditions were associated with cervical cancer screening, and higher education, being from the White or Indian/Asian population group, greater wealth, having a health insurance, and suffering from two or more chronic condtions were associated with breast cancer screening. Conclusions: Cancer screening coverage remains low among elderly women in South Africa in spite of the national guideline recommendations for regular screening in order to reduce the risk of dying from these cancers if not detected early. There is a need to improve accessibility and affordability of early cervical and breast cancer screening for all women to ensure effective prevention and management of cervical and breast cancer.

여의도공원의 경제적 가치평가: 二段階 二選 假想價値推定法을 적용하여 (Economic Valuation of Yeido Park: Application of Double-Bounded Dichotomous Choice Contingent Valuation Method)

    • 한국조경학회지
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    • 제26권3호
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    • pp.90-103
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    • 1998
  • The purposes of this study are to estimate the economic value and reasonable entrance fee of the Yeido Park, which is under construction in Seoul, by conduct the face-to-face interview. A total of 645 daults were selected by two stage cluster sampling. The senario was designed to meet the requirements for doubgle-bounded dichotomous choice CVM, and distributed with the photograph to epict and compare the current and suggested conditions. A donation vehicle and entrance fee were utilized to find the possibility of strategic behaviors and protest zero, and to make the data estimatable tfor interval censored survival analysis. Date was calibrated by the survival analysis to eleminate the 'fat-tail problem'. Weibull distribution was assumed as a baseline distrubution. The mean WTP of donation and entrance fee was ₩5,281 and ₩783, respectively. The economic value of this park was determined by aggregating the mean value, giving a total WTP for the population of ₩36,861,645,000. This economic value was composed with the use value and existence value. The calibrationi of the Weibull proportional hazard model showed that nearness to the park, age, intention to isit the park, and educational attainment were significant independent variable to influence an amount of donation.

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이동통신시장의 주요통계지표를 이용한 산업수명주기 유형화에 관한 연구 (An Approach to Classification of Industry Life Cycle using Main Statistics Index in the Mobile Market)

  • 정선필;경종수
    • 한국조사연구학회지:조사연구
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    • 제7권1호
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    • pp.55-84
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    • 2006
  • 본 연구는 이동통신시장의 주요통계지표를 이용하여 이동통신시장의 산업수명주기(Industry Life Cycle)(태동기-성장기-성숙기)를 유형화 하고자 하였다. 분석 모형은 2단계로 구분되며, 1단계 분석에서는 이동전화보급률을 기준으로 이동통신시장의 발전단계를 유형화하고, 2단계 분석에서는 주요통계지표를 비교분석하여 이동통신시장의 발전단계별 시장특성을 제시한다. 1단계 분석결과 군집분석을 이용하여 이동통신시장의 발전단계(태동기-성장기-성숙기)별로 국가군이 유형화되었으며, 발전단계별 군집은 국가경제의 발전수준과 상관관계가 있는 것으로 파악되었다. 2단계 분석결과 주요통계지표에 대한 비교분석을 통한 이동통신시장의 발전단계별 시장특성은 다음과 같다. 첫째, 시장구조지표 중에서 HHI(시장집중률)은 성장기와 성숙기보다 태동기에 매우 높은 것으로 나타났다. 둘째, 시장효율성지표에서 ARPU(사용자당 평균수익)와 RPM(분당수익)은 태동기에서 성장기, 성숙기로 갈수록 높았다. 셋째, 시장성과지표인 EBITDA 마진율은 태동기에는 매우 높지만 성장기, 성숙기에는 상대적으로 낮은 것으로 파악되었다. 결과적으로 이동통신시장의 주요통계지표를 이용하여 특정 국가의 이동통신시장이 산업수명주기 상 어떤 위치에 있는지를 파악함으로써 시장환경 변화에 대응할 수 있는 정책적, 전략적 시사점을 찾을 수 있었다.

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Health assessment of RC building subjected to ambient excitation : Strategy and application

  • Mehboob, Saqib;Khan, Qaiser Uz Zaman;Ahmad, Sohaib;Anwar, Syed M.
    • Earthquakes and Structures
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    • 제22권2호
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    • pp.185-201
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    • 2022
  • Structural Health Monitoring (SHM) is used to provide reliable information about the structure's integrity in near realtime following extreme incidents such as earthquakes, considering the inevitable aging and degradation that occurs in operating environments. This paper experimentally investigates an integrated wireless sensor network (Wi-SN) based monitoring technique for damage detection in concrete structures. An effective SHM technique can be used to detect potential structural damage based on post-earthquake data. Two novel methods are proposed for damage detection in reinforced concrete (RC) building structures including: (i) Jerk Energy Method (JEM), which is based on time-domain analysis, and (ii) Modal Contributing Parameter (MCP), which is based on frequency-domain analysis. Wireless accelerometer sensors are installed at each story level to monitor the dynamic responses from the building structure. Prior knowledge of the initial state (immediately after construction) of the structure is not required in these methods. Proposed methods only use responses recorded during ambient vibration state (i.e., operational state) to estimate the damage index. Herein, the experimental studies serve as an illustration of the procedures. In particular, (i) a 3-story shear-type steel frame model is analyzed for several damage scenarios and (ii) 2-story RC scaled down (at 1/6th) building models, simulated and verified under experimental tests on a shaking table. As a result, in addition to the usual benefits like system adaptability, and cost-effectiveness, the proposed sensing system does not require a cluster of sensors. The spatial information in the real-time recorded data is used in global damage identification stage of SHM. Whereas in next stage of SHM, the damage is detected at the story level. Experimental results also show the efficiency and superior performance of the proposed measuring techniques.

Prevalence of Tobacco and Alcohol Consumption among Fishermen in Udupi Taluk, Karnataka, India: a Cross-Sectional Study

  • Rane, Prasad Pramod;Narayanan, Prakash;Binu, VS;Unnikrishnan, Bhaskaran
    • Asian Pacific Journal of Cancer Prevention
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    • 제17권4호
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    • pp.1733-1737
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    • 2016
  • Background: Stress associated with fishing is known to trigger consumption of alcohol and tobacco among fishermen. This study aimed to assess the prevalence of tobacco and alcohol consumption among fishermen in Udupi Taluk in the state of Karnataka, India, and to study associations with health status and job stress. Materials and Methods: The study was conducted among 825 fishermen in Udupi Taluk of Karnataka between January-June 2015, using a two stage cluster sampling procedure. Associations between variables of interest were assessed using multivariable analysis and logistic regression models. Results: The prevalences of consumption of tobacco, alcohol and either of these substances were 64.2%, 45.6% and 86.9% respectively. There was a positive association between alcohol and any form of tobacco consumption with income but none with respondent's job stress and health status. Conclusions: Our study concluded that fishermen with poor health status are seen more among tobacco and alcohol users.

부모의 양육유형이 사교육비지출과 자녀의 학업성적에 미치는 영향: 사교육비지출의 매개효과를 중심으로 (The Effect of Parenting Styles on Private Educational Expenditure and Academic Performance of Children: Focusing on Mediation Effect of Private Educational Expenditure)

  • 이성림
    • Human Ecology Research
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    • 제56권5호
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    • pp.461-472
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    • 2018
  • Using a sample of third grade middle school students from the forth wave of Children and Youth Panel Survey in 2012, the mediation effects of private educational expenditure between parenting styles and children's academic performance were investigated by applying factor, cluster, tobit, and two stage regression analysis. The major results were as follows. First, four types of parenting style were identified. The most frequent parenting style was ambivalent parenting (tiger parenting) which was followed by authoritative parenting. Second, compared to permissive parenting style, ambivalent, authoritative, and authoritarian parenting styles were significantly associated with more private educational expenditures. Third, more private educational expenditures were significantly associated with higher academic performance of children. I found both a full mediation effect of private educational expenditure for ambivalent and authoritarian parenting styles, and a partial mediation effect for authoritative parents. Authoritative parenting style has a negative moderating effect on the relationship between household income and private educational expenditure, along with a positive direct effect on the academic performance of children. The results suggested that an authoritative parenting style was related with higher academic performance of children with less private educational expenditures compared to other parenting styles. The results also implied that the public policies to enhance authoritative parenting style among parents would be effective to reduce household's private educational expenditures.

Weighted Local Naive Bayes Link Prediction

  • Wu, JieHua;Zhang, GuoJi;Ren, YaZhou;Zhang, XiaYan;Yang, Qiao
    • Journal of Information Processing Systems
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    • 제13권4호
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    • pp.914-927
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    • 2017
  • Weighted network link prediction is a challenge issue in complex network analysis. Unsupervised methods based on local structure are widely used to handle the predictive task. However, the results are still far from satisfied as major literatures neglect two important points: common neighbors produce different influence on potential links; weighted values associated with links in local structure are also different. In this paper, we adapt an effective link prediction model-local naive Bayes model into a weighted scenario to address this issue. Correspondingly, we propose a weighted local naive Bayes (WLNB) probabilistic link prediction framework. The main contribution here is that a weighted cluster coefficient has been incorporated, allowing our model to inference the weighted contribution in the predicting stage. In addition, WLNB can extensively be applied to several classic similarity metrics. We evaluate WLNB on different kinds of real-world weighted datasets. Experimental results show that our proposed approach performs better (by AUC and Prec) than several alternative methods for link prediction in weighted complex networks.

공동연구수행체제 및 참여기업의 기술획득전략-유형별 기업화성과 분석- (Technology Sourcing Strategies and Cooperative Patterns in Vertical Cooperative R&D Projects)

  • 이철원;배종태
    • 기술혁신연구
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    • 제3권1호
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    • pp.1-34
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    • 1995
  • Since 1982, the government of Korea has actively promoted vertical cooperative R&D programs between government-sponsored research institutes (GRIs) and private firms. A number of firms participated in the programs because cooperative R&D could lower the risk and could contribute to rapid commercialization of many technologies. This paper examines the effectiveness of vertical cooperative R&D projects by the modes of cooperation between GRIs and industrial firms, and analyzes the performance of participating firms' technology sourcing strategies for commercial utilization of cooperative R&D results at the project performed from 1982 to 1989 under the Government-Industry Cooperative R&D Program sponsored by the Ministry of Science and Technology(MOST) in Korea. The cooperative R&D projects are classified into 4 groups by two criteria, i.e., the level of participation of firms, and the breadth of cooperation. The findings suggest that firms should actively participate in cooperative R&D projects. In addition, in order to enhance commercial success, cooperation between GRIs and industrial firms should not be limited to R&D stage only. The breadth of cooperation should be extended to commercialization stage. Small- and medium-sized firms participating in vertical cooperative R&D projects in Korea usually lack internal technological capabilities that are needed to commercialize the results of cooperative R&D. Three different technology sourcing strategies - exclusive cooperative R&D strategy, in-house development augmented cooperative R&D strategy, and licensing-in supplemented cooperative R&D strategy - are empirically derived through cluster analysis of the relative usage rates cooperative R&D and of other supplementary technology acquisition methods. The findings suggest that the firms participating in vertical cooperative R&D projects should try to utilize other supplementary technology acquisition methods in order to achieve commercial utilization of the vertical cooperative R&D results.

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취업과 결혼상태가 남녀의 건강에 미치는 영향 (Effects of Employment and Marital Status on Health Status of Women and Men)

  • 박은옥
    • 지역사회간호학회지
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    • 제6권1호
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    • pp.84-97
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    • 1995
  • There is a widespread concern that women's increasing involvement in dual role (job plus family role) may harm their physical health. Longevity of women is longer than that of men. By contrast, prevalence rate is higher in women than men, and No. of prevalence days, No. of days in bed and No. of days with treatment are more in women. Generally, women live longer, but women are worse in health status than men. Rate of labor participation in women is increasing gradually in Korea. This study presents an analysis of the relationships between employment. marital status and health for both Korean women and men to examine how women's increasing involvements in dual role affect their physical health. The data used in this analysis were collected by The National Statistical Office in the spring of 1992. Households, which were sampled by using a three-stage stratified cluster sampling method, were interviewed. Response rate was 99.43%. Of these, student or widowed or divorced people were excluded. 47,552 women and men aged 21-50 were available for the analysis. Health status was measured by self-assessed health status (1=excellent, 5=poor), No. of prevalent days, No. of days with treatment, and No. of days in bed in two previous weeks. And control variables are age, and education. Research findings are as follows : 1. Men have better self-rated health, fewer prevalent days, fewer days in bed, and fewer days with treatment than women. 2. The employed are more healthier than the non-employed. 3. Unmarried people are more healthier than married people. 4. Interaction effects of sex, marital status, employment are significant. This finding shows that effects of empolyment, marital status on health status is not same for women and men. 5. For male, employed people are more healthier than non-employed people. Unmarried people are more healthier than married people. This differences are significant. For female, The employed are more healthier than the non-employed. However, no differences are noticed between the married and the unmarried in health status. In conclusion, there is no evidence that women's involvements in dual role affect their physical health negatively.

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