• 제목/요약/키워드: variance structure

검색결과 534건 처리시간 0.033초

치약 종류에 따른 유치의 표면 변화 (Change in surface of primary tooth using different type of toothpaste)

  • 최정옥;남설희
    • 한국치위생학회지
    • /
    • 제14권2호
    • /
    • pp.281-286
    • /
    • 2014
  • Objectives : The aim of this study is to evaluate the surface changes of enamel specimen, tooth structure by toothpastes in child and adult. Methods : Experimental teeth were collected from extracted human primary teeth. 120 enamel specimens were prepared by cutting the teeth into $2{\times}3{\times}2mm$ blocks using diamond saw and the specimens were assigned to 3 groups. Group 1 was used as control with no treatment. Group 2 was treated with child toothpaste and Group 3 was treated with adult toothpaste on primary enamel surface for 3 minutes daily over 4 weeks. The specimens were immersed into individual container having artificial saliva and the artificial saliva was changed every day. The electron probe micro analyzer(EPMA) provided weight percent(wt%) of calcium(Ca) and phosphorous(P) on enamel surface. The morphology was analyzed by scanning electron microscopy(SEM). Data were analyzed by one-way analysis of variance(ANOVA) and Tukey's test post-hoc test using SPSS(Version 20, SPSS Inc., Chicago, USA). Level of significance was set at 0.05. Results : The surface changes of the primary teeth revealed a significant difference during 4 weeks. Calcium(Ca) and phosphorous(P) levels were found the weight percent difference and a rough enamel surface was seen on SEM after adult toothpaste application. Conclusions : The changes in Ca and P and the morphological surface were affected by the primary tooth treated with adult toothpaste. Enamel surface showed significant differences during 4 weeks.

DEM에 의해 추출된 지형인자의 공간상관성을 기반으로 한 수문학적 응답구조의 해석 (The Analysis of Hydrological Response Structure Based on Spatial Correlation of Extracted Geomorphic Variables by Using DEM)

  • 김주철;최용준;김재한
    • 대한공간정보학회지
    • /
    • 제18권2호
    • /
    • pp.69-78
    • /
    • 2010
  • 유역에서의 수문지형학적 특성들은 유출현상과 깊은 상관성을 가지고 있다. 지리정보체계의 발달은 양자간의 역학관계를 규명하는데 커다란 도움을 주었다. 본 연구에서는 이러한 지형인자 중 수문응답과 밀접한 관계로 알려진 국부경사와 지표면거리에 대한 분석을 실시하였다. 그러나 이상의 지형인자는 각 pixel별 변동성이 매우 크기 때문에 DEM으로부터 추출된 자료를 직접 사용하는 것은 한계를 가지게 된다. 따라서 공간상관성을 고려한 분포도의 통계적 특성을 이용해 수문응답함수 특성과 분포된 지형학적인자간의 관계를 살펴보았다. 분석결과 국부경사는 첨두유량에, 지표면거리는 첨두유량, 평균 및 분산에 영향을 미치는 것으로 나타났다. 향후 이러한 수문지형학적 분석 기법은 DEM자료로부터 수문응답을 직접 유추할 수 있는 유용한 기법으로 발전될 수 있을 것으로 기대된다.

비선형 형상 견인 어레이를 위한 빔형성 기법 (A Beamforming Method for a Perturbed Linear Towed Array)

  • 김승일;도경철;오원천;윤대희;이충용
    • 한국음향학회지
    • /
    • 제21권5호
    • /
    • pp.478-484
    • /
    • 2002
  • 표적 탐지를 위한 선형 견인 어레이는 해수의 움직임이나 견인선의 기동 방향 등에 의해 그 형상이 비선형화 된다. 이러한 비선형성의 존재는 입사신호의 파라미터 추정 오차를 유발하므로 본 논문에서는 비선형 형상의 견인 어레이를 위한 빔형성 기법을 제안한다. 제안된 기법은 두 개의 보조센서를 사용하여 수동 견인 어레이의 첫 번째 하이드로폰과 마지막 하이드로폰의 위치를 파악한 후, 두 하이드로폰 사이의 비선형 형상조향 벡터를 선형화 (Linearization)한다. 실제 수중환경에서의 컴퓨터 모의 실험을 통하여 성능 분석을 행한 결과, 비선형 견인 어레이의 형상에 관계없이 빔패턴은 이상적인 형태를 지님을 확인하였다. 그리고 다양한 입사신호의 신호 대 잡음비 환경 하에서 위상 성분 추정의 한계를 보임으로써 제안된 기법의 입사각 추정 성능을 평가하였으며, 이와 더불어 선형 형상을 가정한 바틀렛 빔형성 기법과의 비교 분석 결과, 현격한 성능 차이를 보였음을 확인하였다.

지역예측모델 영역 크기에 따른 집중호우 수치모의 민감도 실험 (A Study on Sensitivity of Heavy Precipitation to Domain Size with a Regional Numerical Weather Prediction Model)

  • 민재식;노준우;지준범;김상일
    • 대기
    • /
    • 제26권1호
    • /
    • pp.85-95
    • /
    • 2016
  • In this study, we investigated the variabilities of wind speed of 850 hPa and precipitable water over the East Asia region using the NCEP Final Analysis data from December 2001 to November 2011. A large variance of wind speed was observed in northern and eastern China during the winter period. During summer, the regions of the East China Sea, the South Sea of Japan and the East Sea show large variances in the wind speed caused by an extended North Pacific High and typhoon activities. The large variances in the wind speed in the regions are shown to be correlated with the inter-annual variability of precipitable water over the inland region of windward side of the Korean Peninsula. Based on the investigation, sensitivity tests to the domain size were performed using the WRF model version 3.6 for heavy precipitation events over the Korean Peninsula for 26 and 27 July 2011. Numerical experiments of different domain sizes were set up with 5 km horizontal and 50 levels vertical resolutions for the control and the first experimental run, and 9 km horizontal for the second experimental run. We found that the major rainfalls correspond to shortwave troughs with baroclinic structure over Northeast China and extended North Pacific High. The correlation analysis between the observation and experiments for 1-h precipitation indicated that the second experiment with the largest domain had the best performance with the correlation coefficient of 0.79 due to the synoptic-scale systems such as short-wave troughs and North Pacific High.

RAPD 분석(分析)에 의한 전나무 천연집단(天然集團)의 유전변이(遺傳變異) (Genetic Variation in the Natural Populations of Abies holophylla Max. Based on RAPD Analysis)

  • 김인식;현정오
    • 한국산림과학회지
    • /
    • 제88권3호
    • /
    • pp.408-418
    • /
    • 1999
  • 전나무 천연집단의 유전적 다양성 및 유전적 구조를 추정하기 위해서 RAPD 표지자를 사용하였으며, 이의 통계적 분석에 AMOVA 방법을 이용하였다. 전나무 집단 전체의 평균 다형성 RAPD 표지자 비율은 71.9%였으며, 전체 변이량의 대부분은 집단내 개체간의 차이(80.2%)로 설명이 가능하였다. 집단간의 유전적 분화정도(${\Phi}_{ST}$)는 0.198로 조사되었다. 전체 집단을 태백산맥과 소백산맥 두 지역으로 나누어 분석하였을 때, 지역간 차이로 설명할 수 있는 변이량이 8.5%로 나타났으며, 통계적 유의성을 확인할 수 있었다. Bartlett 통계량에 의해 집단간 분산의 이질성을 조사한 결과, 태백산 집단과 가리왕산 집단이 특히 이 질적인 것으로 나타났으며, 전반적으로 태백산맥 지역의 집단들이 소백산맥 지역의 집단들 보다 상대적으로 유전적 이질성이 큰 것으로 나다났다. 마지막으로 기존 통계량과의 비교를 통해서 유전변이 분석에 있어서 AMOVA 방법의 적용 가능성에 대해서 논의하였다.

  • PDF

LOV를 이용한 가치(價値)시스템 세분화(細分化) (The Segmentation of Value System Used by LOV)

  • 심종섭
    • 산학경영연구
    • /
    • 제14권
    • /
    • pp.129-148
    • /
    • 2001
  • 이 논문은 소비자의 심리묘사적변수(psychographic variables)들로 구성된 LOV(list of values)를 조사하고, 이 LOV를 이용한 소비자들의 가치체계(value system)를 세분화하는 것을 목적으로 한다. 접근방법으로서는 Rokeach의 RVS, Kahle의 LOV, 그리고 Razzaque의 Asian Values를 참고하고, 한국적 가치를 추가한 모형을 개발하여, 한국 소비자들의 가치세분화를 진행하였다. 연구결과 LOV를 이용한 우리나라 소비자들의 가치체계(value system)는 (1)영향력에 관한 가치, (2)배금성에 관한 가치, (3)최신성에 관한 가치, (4)모험성에 관한 가치, (5)구원에 관한 가치, (6)사회성에 관한 가치, (7)호기심에 관한 가치, (8)영적 성향에 관한 가치, (9)보수성과 관련된 가치의 순서로 구분이 되었다. 이는 우리나라 소비자들의 가치중심의 시장세분화에 참고자료가 될 것으로 믿는다. 이상의 한국적 가치영역과 인구통계적 변수와의 관계를 분석해 본 결과 성별, 결혼관계, 학력수준, 직업, 가족월총수입, 가족구성형태, 연령 등 전반적 인구통계적 변수와 긴밀한 관계가 있는 것으로 나타났다.

  • PDF

일 의료원의 간호조직 효과성에 관한 연구 (Study on the Effectiveness of Nursing Organization of one tertiary Hospital)

  • 박영주;이숙자;장성옥;;이은숙
    • 간호행정학회지
    • /
    • 제3권2호
    • /
    • pp.109-122
    • /
    • 1997
  • This Study was dosigned to test the relationship between effectiveness of nursing organization and related variables of organization on the perspectives of total quality management, The data were collected through self reported questionnaires from 138 nurses working in, 288 patients hospitalized in one tertiary hospital in Seoul from May 30 to October 10 in 1996. The data were analyzed by using the pc-SAS program. The information was obtained of descriptive statistics, correlation analysis, multiple regression, ANOVA & Tukey's multiple comparison test. Results showed that the managing change, the managing job design, the managing conflict, the formation and the centralization of nursing organization structure were shown to be relating variables for nurses' job satisfaction. Especially the managing change was the predictor of nurses' job satisfaction, It explained 57% of total variance. According to clustor analyses of the variables of the managing change, the managing job design, the managing conflict, the nursing units were divided three clusters and according to ANOVA, there was significint difference in nurses' job satisfaction The nurses' job satisfaction was higher in the nursing units revealed to have high job management score. But there was no significant difference in patient satisfaction among three clusters.

  • PDF

심리적 인슐린저항성 측정도구 개발 (Development of a Psychological Insulin Resistance Scale for Korean Patients with Diabetes)

  • 송영신;전영희;조정화;김보현
    • 대한간호학회지
    • /
    • 제46권6호
    • /
    • pp.813-823
    • /
    • 2016
  • Purpose: This study was done to develop and validate a measure to evaluate the Korean version of psychological insulin resistance (K-PIR) in patients with diabetes in Korea. Methods: Items were initially generated from literature reviews and interviews with 19 patients with diabetes. The content validity of the items was evaluated by experts. Participants were 424 patients with diabetes recruited through convenience sampling. A cross-sectional survey was designed for item-analysis, exploratory factor analysis with principal axis factoring, and confirmatory factor analysis. Cronbach's alpha was calculated to measure the internal consistency. Results: For the 24 items of the Korean version of psychological insulin resistance, six items were eliminated because of low correlation with the other items. Exploratory factor analysis with 18-item showed that two factors (psycho-cognitive factor and supportive factor) explained 41.8% of the variance, and the factor structure of K-PIR model had a good fit. Internal consistency of K-PIR with 18 items revealed good reliability. Conclusion: The findings show that the K-PIR is reliable for measuring the psychological resistance to insulin therapy for Korean patients with diabetes. However, further study is needed to evaluate the validation because the proportion of variation of K-PIR was low in this study.

Genetic Diversity and Population Genetic Structure of Cephalotaxus koreana in South Korea

  • Hong, Kyung Nak;Kim, Young Mi;Park, Yu Jin;Lee, Jei Wan
    • 한국자원식물학회지
    • /
    • 제27권6호
    • /
    • pp.660-670
    • /
    • 2014
  • The Korean plum yew (Cephalotaxus koreana Nakai) is a shade-tolerant, coniferous shrub. The seeds have been used as a folk medicine in Korea, and an alkaloid extract (HTT) is known to have anticancer properties. We estimated the genetic diversity of 429 trees in 16 populations in South Korea using 194 polymorphic amplicons from seven combinations of AFLP primer-restriction enzymes. The average number of effective alleles and the percentage of polymorphic loci were 1.37 and 79.4%, respectively. Shannon's diversity index and the expected heterozygosity were 0.344 and 0.244, respectively. We divided 16 populations into four groups on the UPGMA dendrogram and the PCA biplot. The first two principal components explained 84% of the total genetic variation. Genetic differentiation between populations explained 14% of total genetic variation, and the remaining 86% came from difference between individuals within populations, as determined by an analysis of molecular variance (AMOVA). However, the genetic differentiation did not correlate with the geographic distance between populations from the Mantel test. The Bayesian statistics, which are comparable to Wright's $F_{ST}$ and Nei's $G_{ST}$, were ${\theta}^I=0.406$ and ${\theta}^{II}=0.172$, respectively. The population genetic diversity was slightly lower, and the strength of genetic differentiation was much weaker, than the average of those plants having similar life histories, as assessed using arbitrary marker systems. We discuss strategies for the genetic conservation of the plum yew in Korea.

Climate Change Scenario Generation and Uncertainty Assessment: Multiple variables and potential hydrological impacts

  • 권현한;박래건;최병규;박세훈
    • 한국수자원학회:학술대회논문집
    • /
    • 한국수자원학회 2010년도 학술발표회
    • /
    • pp.268-272
    • /
    • 2010
  • The research presented here represents a collaborative effort with the SFWMD on developing scenarios for future climate for the SFWMD area. The project focuses on developing methodology for simulating precipitation representing both natural quasi-oscillatory modes of variability in these climate variables and also the secular trends projected by the IPCC scenarios that are publicly available. This study specifically provides the results for precipitation modeling. The starting point for the modeling was the work of Tebaldi et al that is considered one of the benchmarks for bias correction and model combination in this context. This model was extended in the framework of a Hierarchical Bayesian Model (HBM) to formally and simultaneously consider biases between the models and observations over the historical period and trends in the observations and models out to the end of the 21st century in line with the different ensemble model simulations from the IPCC scenarios. The low frequency variability is modeled using the previously developed Wavelet Autoregressive Model (WARM), with a correction to preserve the variance associated with the full series from the HBM projections. The assumption here is that there is no useful information in the IPCC models as to the change in the low frequency variability of the regional, seasonal precipitation. This assumption is based on a preliminary analysis of these models historical and future output. Thus, preserving the low frequency structure from the historical series into the future emerges as a pragmatic goal. We find that there are significant biases between the observations and the base case scenarios for precipitation. The biases vary across models, and are shrunk using posterior maximum likelihood to allow some models to depart from the central tendency while allowing others to cluster and reduce biases by averaging. The projected changes in the future precipitation are small compared to the bias between model base run and observations and also relative to the inter-annual and decadal variability in the precipitation.

  • PDF