• Title/Summary/Keyword: Two types of correlations

Search Result 145, Processing Time 0.03 seconds

Multi-Level Rotation Sampling Designs and the Variances of Extended Generalized Composite Estimators

  • Park, You-Sung;Park, Jai-Won;Kim, Kee-Whan
    • Proceedings of the Korean Association for Survey Research Conference
    • /
    • 2002.11a
    • /
    • pp.255-274
    • /
    • 2002
  • We classify rotation sampling designs into two classes. The first class replaces sample units within the same rotation group while the second class replaces sample units between different rotation groups. The first class is specified by the three-way balanced design which is a multi-level version of previous balanced designs. We introduce an extended generalized composite estimator (EGCE) and derive its variance and mean squared error for each of the two classes of design, cooperating two types of correlations and three types of biases. Unbiased estimators are derived for difference between interview time biases, between recall time biases, and between rotation group biases. Using the variance and mean squared error, since any rotation design belongs to one of the two classes and the EGCE is a most general estimator for rotation design, we evaluate the efficiency of EGCE to simple weighted estimator and the effects of levels, design gaps, and rotation patterns on variance and mean squared error.

  • PDF

The Relationships between the Types of Perceived Risk and the Use of Information Sources in Clothing-Purchase. (의복 구매시 인지되는 위험 유형과 정보원 활용과의 관계)

  • Ok Sun Kyung;Lee Eun Young
    • Journal of the Korean Society of Clothing and Textiles
    • /
    • v.10 no.3
    • /
    • pp.49-61
    • /
    • 1986
  • The purpose of this study is to analyze the types of perceived risk and the use of information sources respectively in clothing-purchase and ; study the correlations between the two variables and also ; study how the socioeconomic status impacts on the use of information sources. The questionnaires were administered to a sample of 393 housewives living in Seoul. For statistical analysis, the Pearson's product-moment correlation coefficients, analysis of variance, and Neuman-keul's test were used. The results were as follows : 1) There were significant differences in the types of perceived risk, reviewing these by clothing use and fashion Stage. 2) There were significant differences in the use of information sources, reviewing these by clothing use and fashion stage. 3) There were significant correlations between the types of Perceived risk and the use of information sources, reviewing these by clothing use and fashion stage. 4) In each fashion stage, there were partly significant differences in the types of perceived risk, reviewing these by SES. 5) In each fashion stage, there were partly significant differences in the use of information sources, reviewing these by SES.

  • PDF

Relationship between Chromatic Characteristics, Chemical Components and Carbonization in Leaf Tobacco during Storage (저장중 원료 잎담배의 탄화발생과 색상 및 화학성분과의 관계)

  • 정기택;안대진;김미주;이종철
    • Journal of the Korean Society of Tobacco Science
    • /
    • v.23 no.2
    • /
    • pp.149-155
    • /
    • 2001
  • This study was carried out to evaluate the correlations among degree of carbonization, chemical components and chromatic characteristics, and to establish the criterion of carbonizaion in leaf tobacco during aging storage. The flue-cured (B2O) and burley (B2T) leaf tobaccos were redried with conventional practices for each other type, and moisture contents of leaf tobaccos were adjusted to 13, 15, 17 and 19% after redrying. The leaf tobaccos were packed in carton box and stored for 8 months in the controlled-environment rooms($35^{\circ}C$, 65% R.H. and $40^{\circ}C$, 80% R.H.). Degree of carbonization, chemical components, and chromatic characteristics(L ; black-white, a ; red to green, b ; yellow to blue) were invetigated every month. Carbonization Index (C.I.) was established as (equation omitted) in accordance with degree of carbonization in two types. The C.I. value of flue-cured leaf(56.5) for slight carbonization was higher than that of burley leaf(48.0). C.I. and rate of usable leaf, L and b were positively correlated in two types. C.I. was significantly shown positive correlation with pH in two types. The correlations between the predicted and the observed values of slight carbonizating times(month after storage) using C.I. and pH were positive significant in two types. The results suggest that cabonization index may be useful to forecast and prevent the carbonization, and pH may be useful to estimate cabonization indirectly for flue-cured and burley leaves during aging storage.

  • PDF

AN EMPIRICAL BAYESIAN ESTIMATION OF MONTHLY LEVEL AND CHANGE IN TWO-WAY BALANCED ROTATION SAMPLING

  • Lee, Seung-Chun;Park, Yoo-Sung
    • Journal of the Korean Statistical Society
    • /
    • v.32 no.2
    • /
    • pp.175-191
    • /
    • 2003
  • An empirical Bayesian approach is discussed for estimation of characteristics from the two-way balanced rotation sampling design which includes U.S. Current Population Survey and Canadian Labor Force Survey as special cases. An empirical Bayesian estimator is derived for monthly effect under presence of two types of biases and correlations It is shown that the marginal distribution of observation provides more general correlation structure than that frequentist has assumed. Consistent estimators are derived for hyper-parameters in Normal priors.

Thermal Performance of a Finned-tube Heat Exchanger used in Condensing Gas Boiler

  • Kang, Hie-Chan;Lim, Bok-Bin;Lee, Jung-Man;Kim, Moo-Han
    • International Journal of Air-Conditioning and Refrigeration
    • /
    • v.17 no.2
    • /
    • pp.61-67
    • /
    • 2009
  • In the present study, an experiment was conducted to investigate the heat and mass transfer performance of heat exchangers used in the condensing gas boiler. Two types of spiral circular fin-tube heat exchangers and a plain tube were tested in the flue gas of propane and dry air. Heat and mass transfer coefficients were measured and compared with the previous correlations. The experimental data for the sensible heat transfer of the plain tube reasonably agreed with the previous correlations for dry air and flue gas. However, the mass transfer coefficient of the plain tube was greater than the previous correlations. The pH, $NO_x$, and $SO_x$ data of condensate were provided.

Antigenic-types of Salmonella pullorum and Salmonella gallinarum isolated from poultry in Korea (우리나라의 닭에서 분리한 Salmonella pullorum과 Salmonella gallinarum의 항원형)

  • Woo, Yong-ku;Kim, Bong-hwan
    • Korean Journal of Veterinary Research
    • /
    • v.38 no.4
    • /
    • pp.777-783
    • /
    • 1998
  • Antigenic types of 114 Salmonella pullorum and 152 Salmonella gallinarum field isolates were evaluated. All 3 antigenic types were identified among field isolates of S pullorum by factor-serum analysis but the majority of them were standard type(90.4%). Of the 114 S pullorum isolates, only eight(7.0%) were intermediate type and 3(2.6%) were variant type. Using the ammonium sulfate precipitation(ASP) test, one-hundred and three(90.4%) S pullorum isolates were standard type, while intermediate and variant types were 8.4% and 1.4%, respectively. One-hundred and fifty-two S gallinarum isolates were identified as standard type by ASP test and serological analysis. According to the random amplified polymorphisms of DNA(RAPD) patterns, most of S pullorum isolates were differentiated with 3 types in their fragment-patterns. No correlations were found between SDS-PAGE profiles and antigenic types of S pullorum isolates.

  • PDF

Study on Pressure drop characteristics in HTS cable core with two flow passages

  • Lee, Jun-Kyoung;Kim, Seok-Ho;Kim, Hae-Joon;Cho, Jeon-Wook
    • Progress in Superconductivity and Cryogenics
    • /
    • v.10 no.4
    • /
    • pp.33-37
    • /
    • 2008
  • The main objective of this study is to identify the pressure drop characteristics of coolant flow passages of 154kV/1GVA High Temperature Superconducting (HTS) power cable, experimentally. The passages were consisted of two parts, the one is the circular path with spiral ribs in the core to cool the cable conductor layer and the other is annular path with spirally corrugated outer wall to cool the shield layer. Thus the experiments to acquire the pressure drop data were performed with two types of circular spiral tubes and eight types of the concentric annuli in various range of Reynolds number. The pressure drops in the core tubes and the annuli were much higher than those in the tubes with smooth surface. Therefore, modified correlations to present the experimental results in each flow passage were suggested.

Mercury Exchange Flux from Two Different Soil Types and Affecting Parameters

  • Park, Sang-Young;Kim, Pyung-Rea;Han, Young-Ji
    • Asian Journal of Atmospheric Environment
    • /
    • v.7 no.4
    • /
    • pp.199-208
    • /
    • 2013
  • Mercury exchange fluxes between atmosphere and soil surface were measured in two different types of soils; lawn soil (LS) and forest soil (FS). Average Hg emission from LS was higher than from FS although the soil Hg content was more than 2 times higher in forest soil. In LS, Hg emissions were much greater in warm season than in cold season; however, deposition was dominant in FS during warm season because of leafy trees blocking the solar radiation reaching on the soil surface. In both LS and FS, Hg fluxes showed significantly positive correlations with UV radiation and soil surface temperature during cold season. In addition, it was observed that emission showed positive correlation with UV radiation and soil temperature while there was negative relationship between deposition and UV radiation.

Gender Variation in Relation to Resource Allocation in Ambrosia artemisiifolia (Ambrosia artemisiifolia에 있어서 자원분배와 관련된 성비의 변이)

  • Kang, Hyesoon
    • The Korean Journal of Ecology
    • /
    • v.18 no.2
    • /
    • pp.231-241
    • /
    • 1995
  • I examined the relationship between allocations to plant size components such as plant height, total leaf weight, and nuber of branches and to reproductive components such as the number and weight of male and female fowers in three populations of the monoecious, wind-pollinated Ambrosia artemisiifolia. In particular, the two types of gender of plants, phenotypic and functional gender, were related to resource allocation. Mean values of all plant size and reproductive components differed significantly among the three populations. Such inter-population differences did not exist for both photosynthetic and reproductive efforts, Plant size components were mostly positively correlated with reproductive components among plants. However, the relationships between photosynthetic effort and reproductive components were largely negative and inconsistent among populations. The phenotypic gender was much lover than 0.5 in all of the three populations. Pairwise correlations between functional gender and each allocation measurement such as plant size components, reproductive components, photosynthetic effort, and reproductive effort were not consistent across the three populations. These results suggest that the gender of A. artemisiifolia measured as flower production responds sensitively to environmental conditions which might differ whithin as well as among populations.

  • PDF

Estimation of Greenhouse Gas Emissions as Highway Design Types by Using Driving Simulator (차량시뮬레이터를 활용한 도로기하구조 조건별 CO2 산정 연구)

  • Chong, Sang Min;Lee, Jong-Hak;Choi, Jaisung;Kim, Jong-Min;Noh, Kwan-Sub
    • International Journal of Highway Engineering
    • /
    • v.16 no.6
    • /
    • pp.129-136
    • /
    • 2014
  • PURPOSES : This study devotes its energies to estimate greenhouse gas emissions for types of horizontal highway designs. METHODS : This paper suggested two types of road scenarios, scenario 1 is made by the lack of road design consistency. Beside scenario 1, scenario 2 is made by good road design. For comparisons of greenhouse gas emissions, driving simulator was used. RESULTS : Emission rates of road scenario 1 are 1.4 times higher than scenario 2 in the driving simulator. CONCLUSIONS : This study may have important implications for contributing to the application of road alignment technology for reduction of greenhouse gases as quantifying the correlations between greenhouse emissions and various road alignments. Consequently, this study will help road designers determine which roads are best alternatives in the process of choosing the roads in the future in terms of environmental benefits.