• 대한환경공학회지
• /
• 제38권2호
• /
• pp.71-78
• /
• 2016

본 연구에서는 낙동강 창녕함안보 구간의 수질을 통계분석을 이용하여 수질 특성을 파악하였다. 다양한 통계분석기법 중에서 상관분석과 주성분분석 및 요인분석을 실시하였으며, 강우에 따른 조류의 천이양상을 연구하였다. 이는 향후 창녕함안보 구간의 수질관리정책 수립을 위한 기초 자료를 구축하는데 매우 중요한 자료이다. 측정 자료의 상관성 분석 결과, 클로로필-a와 조류는 상관성이 유의하지 않게 나타났으며, 요인분석 결과로 3개의 주성분이 추출되었으며, 제 1요인으로는 COD, TOC, BOD, pH, 수온이 분류되었다. 또한, 강우에 따른 조류의 천이양상을 분석한 결과, 강우 후에는 남조류의 수중개체 농도가 감소하는 추세를 보인 반면, 규조류와 녹조류의 개체 농도는 다소 증가하였다.

• International Journal of Human Ecology
• /
• 제4권2호
• /
• pp.77-87
• /
• 2003

This paper tried to construct statistical and econometric models on the basis of economic theory in order to discuss the issue of statistical efficiency and unbiasedness including the sample selection bias correcting problem. Comparative analytical tool were one stage Tobit of Maximum Likelihood estimation and Heckman's two-step Tobit of Ordinary Least Squares. The results showed that the adequacy of model for the analysis on demand and choice, we believe that there is no big difference in explanatory variables between the first selection model and the second linear probability model. Since the Lambda, the self- selectivity correction factor, in the Type II Tobit is not statistically significant, there is no self-selectivity in the Type II Tobit model, indicating that Type I Tobit model would give us better explanation in the demand for and choice which is less complicated statistical method rather than type II model.

• 한국연초학회지
• /
• 제22권2호
• /
• pp.184-189
• /
• 2000

This study was conducted to develop the objective evaluation method for tobacco smoke. The evaluation was carried out by using the data of cut or blended tobacco components, smoke components, electric nose system (ENS), and sensory test. By using the statistical methods, such as cluster analysis, discriminant analysis, factor analysis, correlation analysis, and multiple regression analysis, the relationship among the data of tobacco, smoke, ENS, and sensory evaluation was studied. By the results of cluster analysis, the data from smoke analysis by GC and ENS were able to select the difference of tobacco leaf characteristics. As the results of discriminant analysis, grouping by the components of tobacco leaves and smoke was possible and the results of GC analysis of smoke could be used for discrimination of tobacco leaves. In the results of factor analysis, nicotine, tar, CO, puff No and pH in the smoke were the factors effecting on the tobacco leaf characteristics. From the correlation analysis, aroma, taste, irritation, and smoke volume of sensory test had high relation to tar, p-cresol threonolatone, levoglucosane, and quinic acid- ${\gamma}$ -lactone of smoke. The ENS data showed high efficiency for discriminant analysis and cluster analysis, but it was not good for factor analysis, and correlation analysis. It was possible to estimate tobacco leaves and their blending characteristics by the analytical data of tobacco leaves, smoke, ENS, and sensory test results. By the multiple regression analysis, some correlation among selected chemical components and sensory evaluation were found. This study strongly indicated that the some chemical analysis data was available for the objective evaluation of tobacco sensory attributes.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2001년도 추계학술발표회
• /
• pp.155-159
• /
• 2001

A study on multivariate statistical classification of ground water hydrographs was conducted. The vast data of national ground water monitoring network (78 sites of alluvium) were used. 6 factors were selected to classify the ground water level change. Factor analysis was proved to be useful tool for classifying vast hydrogeological data.

• 한국조리학회지
• /
• 제21권6호
• /
• pp.49-62
• /
• 2015

본 연구의 목적은 외식관련 학술적 연구들에 적용된 통계적 기법의 사용 현황 및 일부 통계적 기법의 잘못된 사용에 대해 고찰해 보고자 하였다. 이러한 목적을 달성하고자 본 연구에서는 2010년부터 2013년도까지 총 4년간 한국조리학회지에 게재된 총 415편 중 자연과학적 연구, 질적 연구, 영문으로 작성된 연구 등을 제외한 총 251편의 학술적 연구를 대상으로 내용분석(content analysis)을 실시하였다. 연구의 결과를 요약하면 다음과 같다. 첫째, 사회과학 연구방법을 사용한 279편의 학술적 연구 중 269편이 양적 연구방법을 사용하였으며 10편의 학술적 연구만이 질적 연구방법을 사용한 것으로 조사되었다. 둘째, 전체 251편의 학술적 연구 중 20편(8.0%)의 연구는 통계방법 또는 통계 프로그램의 이름 등이 명시되어 있지 않은 것으로 나타났다. 셋째, 분석 기간 내에 한국조리학회지에 게재된 학술적 연구의 자료 분석에 가장 많이 사용된 통계 패키지는 SPSS 프로그램으로 나타났다(90.8%). 넷째, 분석대상 전체 251 편의 학술적 연구에 사용된 통계적 기법의 사용빈도를 살펴보면 빈도분석, 신뢰도분석, 탐색적 요인분석, 상관관계 분석, 회귀분석, 구조방정식모형, 확인적 요인분석, T-test, 분산분석, 교차분석 등이 주로 사용되고 있는 것으로 나타났다. 향후 연구에서는 각각의 통계적 기법에서 찾아볼 수 있는 통계적 오류에 대한 검증과 이를 통해 통계적 오류를 최소화시킬 방안이 제시되어야 할 것이다.

• 한국전자파학회:학술대회논문집
• /
• 한국전자파학회 2003년도 종합학술발표회 논문집 Vol.13 No.1
• /
• pp.74-78
• /
• 2003

This paper shows the dosimetric uncertainties of electromagnetic field at in-vivo and in-vitro experiments. For more accurate consequences of these researches, we have tried to find out any correlations among output power, power density and specific absorption rate(SAR) with the results of in-vivo, in-vitro tests and SAR reports of cellular phone and PDA. In the case of in-vivo tests, the power density has close statistical correlations with SAR value and in the event of in-vitro tests, the output power has considerable statistical correlations with SAR containing duty factor. On the other hand, we found that both power density and output power don't have any close correlations with SAR. And, we obtained fitted regression form among frequency, power density and SAR containing duty factor through multiple linear regression analysis.

• 한국디지털건축인테리어학회논문집
• /
• 제13권3호
• /
• pp.15-23
• /
• 2013

As a succeeding analysis on the variables' significance to 'Quality of Life(QOL)'(Kim, Dong-Yoon, 2012a), which has a purpose of trying to enhance the intersubjectiveness by means of quantitive methods to find the factors on the QOL, this study aims at finding the time serial change in the deciding factors to deepen the related researches on the theme. Using the similar statistical methods such as multiple regression and factor analysis for "2012 Seoul Survey" this study shows two similar points and one differentia. The similarities include the fact that five subcategories of happiness have relative statistical importance in the order of (1)financial condition, (2)health condition, (3)social activities, (4)community relationship and (5)family life and the fact that the five subcategories are conceptually different from the 5 deciding factors, which means the possibility to improve the survey design. And the difference is the 5 factors such as (1) social trust - amenities, (2)cultural life, (3)social indiscrimination - hope for elevation, (4)sharing - giving and (5)community spirit which are largely different from preceding study. Although only the first two factors have statistical significance this result has a implication that they reflect the new paradigm of social capital and the essential necessity of human survival; sharing-community-culture.

• 환경위생공학
• /
• 제14권2호
• /
• pp.56-67
• /
• 1999

This study was performed to suggest the basic data and plans for the establishment of safe water supply plans in simple water supply piped system in the rural areas. In 4 different places, 24 points of water sources 36 points of taps from water sources were sampled. Of the whole 60 points, 55 points were ground water and 5 points were surface water. 14 items were measured for the analysis of water quality on each samples. The measured items were analyzed again by statistical method ; cluster analysis and principle components analysis. The results of this study are as followed. 1) In water quality analysis on water sources, 4 items, bacteria, E.coli, NH3-N and Fe exceed the standard. Of 24 points, 20 points(83%) on bacteria, 1 point(4%) on NH3-N and Fe exceed the standard. 2) In water quality analysis on near and remote taps, 4 items, bacteria, E.coli, NH3-N and Fe , exceed the standard. Of 36 points, 20 points (81%) on bactria, 1 pint(3%) on NH3-N and Fe exceed the standard. 3)Cluster analysis on water quality shows the differences by the kinds of water sources, geographical characteristics and distance from water sources. 4) Principle components analysis on ground water shows that Factor 1 and Factor 3 are natural fluctuation by the content of soil. Also, Factor 2 and Factor 4 are penetration of pollutants to underground. Therefore, it is needed to take deeper ground water in order to prevent from pollution in the areas which have ground water as water source . 5) Principle components analysis on surface water shows that Factor 1 is penetration of vacteria from surface to water source when rainfalls. Also, Factor 2 is fluctuation of water quality by the geographical characteristics. Therefore, the counterplans against non-point pollution source must be taken. Filtration and disinfection facilities are needed in the areas which have surface water as water source.

• 한국수학교육학회지시리즈A:수학교육
• /
• 제56권4호
• /
• pp.407-434
• /
• 2017

The purpose of this study is to develop and verify the TPACK measurement tool for middle and high school mathematics teachers in the Korean context. Also, by clarifying the relationship between subordinate factors of Mathematics teachers' TPACK, an attempt was made to provide suggestions on the designs and directions for the in-service and pre-service teacher education and the programs for improving mathematics teachers' TPACK in the future. In order to achieve this goal, TPACK factors of mathematics teachers were extracted by reviewing literature on PCK, MKT, and TPACK. Then, content validity, basic statistical survey, reliability verification, exploratory factor analysis, confirmatory factor analysis, and structural equation model verification were conducted sequentially. At first, preliminary analysis was carried out on 79 mathematics teachers, and 76 items excluding the items with extreme value and reliability were included in the basic statistical analysis. And secondly, an exploratory factor analysis was conducted on 376 mathematics teachers, and this instrument consisted of 7 subordinate factors(CK, PK, TK, PCK, TCK, TPK, TPACK) and 61 items. Also by conducting confirmatory factor analysis and structural equation model test with 254 mathematics teachers, the measurement tool was confirmed the validity and reliability through statistically significant analysis. Then, the importance of integrated knowledge was confirmed by looking at the relationship between the TPACK factors of in-service mathematics teachers. The integrated knowledge(PCK, TCK, TPK) has played a crucial role in the formation of TPACK rather than the knowledge of CK, PK, and TK alone. Finally, the validity of TCK was confirmed through the structural equation modeling of TPACK. TCK not only directly affected TPACK, but also indirectly through TPK. According to these affirmative results, this measurement tool is claimed to be suitable for measuring the factors of Mathematics teachers' TPACK, and also the structural equation model can be regarded as a suitable model for analyzing the structural relationship of mathematics teachers' TPACK.

• 한국지반공학회논문집
• /
• 제24권4호
• /
• pp.89-100
• /
• 2008

국외에서 개발한 상관식이나 도표 등을 활용하여 국내 지반특성을 반영함에 있어 이를 그대로 국내지반에 적용하는 데에는 한계가 있다. 따라서 국내에 적합한 피에조콘계수 활용을 위해서는 국내 지반에 대한 시험결과를 직접적으로 이용하여 피에조콘계수를 결정할 필요가 있다. 이에 본 연구에서는 서해안 시화호 주변에 광범위하게 분포하고 있는 연약지반을 대상으로 실내시험 및 현장시험을 수행한 결과를 피에조콘 관입시험과 비교 분석하고, 비배수전단강도와 콘 관입저항력과의 상관성 분석을 통하여 피에조콘계수를 산정하였다. 또한 산정된 결과의 신뢰성 확보를 위하여 통계분석 기법을 활용하여 연구대상 지역에 적합한 피에조콘계수를 재산정해 보았다.